How messed-up is this. Think head gasket is blown

[Greg Kilgore]

I'm 99.9% sure head gasket is blown.

Don't have coolant in oil. That a good thing. But think coolant is getting in combustion chamber. 

I did compression test.
Got 120psi walked away. Came back to 105psi 15 minutes later.

How hard is it to replace?

https://youtu.be/N31mOtOPuKI?si=nSnuF4-weRU2T10t

Advise?

[Joe Breaux]

Been there..I had to pay to get it done because I had just had back surgery. Did not appear to be to difficult but after replacing gasket we realized the head was cracked..better check yours while it's off. This is a common issue on Hisun engine.I honestly think they don't torque the head bolts during assembly. None of mine were .good luck

[Greg Kilgore]

Thanks for the input. I have the know-how, (with some help, hopefully, from this forum and YT if I have trouble). Don't have a enclosed work space. And it's winter. So I'll probably have to send to a shop.

The closest authorized shop is 3ish hours away and a 2 month wait. May see if any shop is willing to work on it.

Didn't have any issues until I installed that heater. Then it got hot enough to turn on idiot temp light on dash. Because I didn't bleed where coolant line comes out of the head.

Just wondering if I should remove the heater. 

The heater pipes are about 16mm and the radiator hoses are about 22mm. And the way I plumed the thing was to force all the coolant through the heater, but also left a heater bypass. Hand controlled by ball valves. 

Either way the wife blames me for f-ing around with it. LOL Every married man knows how that goes. Got a sign in the yard that says "Property Protected by PMS Security System". LOL

Any way may have to restore coolant system back to stock or build something that will allow the same flow and still go through the heater. I don't know. Anybody have any input.

[Alien10]

Compression test clarification question.

Did you get 120lbs that then bled down to 105 in 15 minutes of sitting?  Or did you do a second test 15 minutes later and only got 105lbs.

Remember, rings and pistons are not complete seals, they all naturally leak.  Max compression is only required to be present during the power stroke, and for a fraction of a second.

If  there's no coolant in the oil, what else has convinced you of a failed head gasket?

You might consider additional testing before tearing into the engine.

 

[Alien10]

Couple of other thoughts...

A head gasket can fail to the oil passages, to the coolant system, or to the outside air.   

Are you getting excessive crank case blow by? 

Is there any external compression leakage?

Are you getting combustion gases in the coolant system?  Cap off  coolant system shouldn't be expelling gases or pressure.

Has the coolant level dropped or increased? 

Does the coolant appear to be contaminated in any way? (Oily, brownish tinge etc.)

Just a few things that came to mind.

Good luck. 

 

[Joe Breaux]

Look for tiny bubbles in the coolant recovery bottle while running and normal temp or hot.  Mine never got coolant in the oil but looked like Alka Seltzer in the recovery bottle.

[Greg Kilgore]

2 hours ago, Alien10 said:

Compression test clarification question.

Did you get 120lbs that then bled down to 105 in 15 minutes of sitting?  Or did you do a second test 15 minutes later and only got 105lbs.

...

I got 120lbs that then bled down to 105 in 15 minutes of sitting.

 

 

2 hours ago, Alien10 said:

Compression test clarification question.

...

If  there's no coolant in the oil, what else has convinced you of a failed head gasket?

...

 

I get air bubbles bubbling up in the radiator while the engine is running.

The Idiot temp light on dash came on after I installed the cab heater and refilled the radiator (thought I had all air out). Has done that a few times but was able to rev engine a few times and it went off while riding 3 days after the heater was installed.

I bleed the coolant system at the bleed screw on the goose neck at the head. Until coolant start to come out. Then run the engine. Then watch the bubbles come to the top of the radiator fill opening. That is shown in the video.

 

2 hours ago, Alien10 said:

Couple of other thoughts...

A head gasket can fail to the oil passages, to the coolant system, or to the outside air.   

Are you getting excessive crank case blow by? 

I may have some blow by but not a lot.

 

2 hours ago, Alien10 said:

...

Is there any external compression leakage?

...

No I don't think so. Can't hear or fill anything. Guess I could use soapy water to make sure. But the head is nice and dusty.

 

2 hours ago, Alien10 said:

...

Are you getting combustion gases in the coolant system?  Cap off  coolant system shouldn't be expelling gases or pressure.

...

I'm getting something bubbling of the radiator with cap off. Guess I could hold a lighter there and see if I get an increase in flame when bubbles pop to see if fuel is present. The bubbling is seen in video.

 

2 hours ago, Alien10 said:

....

Has the coolant level dropped or increased? 

... 

When I open radiator cap when it has been setting for a day or two. There is pressure present. And the radiator is full. No drop nor increase as far as I can tell. I'll check here in a few.

I topped off the overflow jug when I added that cab heater. I should drain it back to normal and monitor.

 

2 hours ago, Alien10 said:

...

Does the coolant appear to be contaminated in any way? (Oily, brownish tinge etc.)

... 

No change color. No oil floating. 

 

2 hours ago, Alien10 said:

...

Good luck. 

 

Thanks I'll need it. 

 

I'm currently giving it the twice over. Been setting a week or so. 

Radiator topped off.

Air at goose neck.

I'm pulling the spark plug. Going to stick a white paper towel in and see what come out. Post after.

[Greg Kilgore]

3 minutes ago, Joe Breaux said:

Look for tiny bubbles in the coolant recovery bottle while running and normal temp or hot.  Mine never got coolant in the oil but looked like Alka Seltzer in the recovery bottle.

Get big bubble in radiator with cap off. It's in the video. I don't think it builds up the pressure to come past the cap. But I'll check in a few and report back.

Thanks.

[Alien10]

A little pressure in the radiator after sitting a few days would seem to preclude a head gasket failure between the combustion chamber and the coolant jackets. Pressure would push coolant into the cylinder or if failed between oil and coolant, into the crank case.   Also when running, a head gasket blown into the cooling system will certainly provide pressure into the cooling system and exiting at the open radiator fill.    There is a tester that will analyze the coolant to see if combustion products are contaminating it.  Not sure if you can borrow one of these from a local auto parts store or not.

There used to be a radiator air pump that you'd use in place of the radiator cap. Pump up pressure in the cooling system and watch the pressure gauge to see if it holds or bleeds off.  

In your video, the bubbles are somewhat consistent in volume over the course of the video with the engine idling.  What happens if you raise the RPMs while watching the coolant in the radiator?   Do the bubbles increase in volume as you would expect if it is coming from a head gasket leak into the cooling system. 

This is more of a guess on what you've found so far, but maybe there is still a big air bubble somewhere in the cooling system that is slowly percolating up as the pump is pumping the coolant. 

 

 

[Greg Kilgore]

26 minutes ago, Alien10 said:

A little pressure in the radiator after sitting a few days would seem to preclude a head gasket failure between the combustion chamber and the coolant jackets. Pressure would push coolant into the cylinder or if failed between oil and coolant, into the crank case.   Also when running, a head gasket blown into the cooling system will certainly provide pressure into the cooling system and exiting at the open radiator fill.    .....

Exactly, just didn't put it as you did.

On 12/9/2024 at 2:48 PM, Greg Kilgore said:

...

Don't have coolant in oil. That a good thing. But think coolant is getting in combustion chamber. 

...

 

26 minutes ago, Alien10 said:

... There is a tester that will analyze the coolant to see if combustion products are contaminating it.  Not sure if you can borrow one of these from a local auto parts store or not.

There used to be a radiator air pump that you'd use in place of the radiator cap. Pump up pressure in the cooling system and watch the pressure gauge to see if it holds or bleeds off.  

...

Didn't know about the gas tester. I'll see if the parts store has something. Thanks.

I've used the radiator pressure tester from auto parts before on my GMC truck. So I should get it again and test the Axis.

26 minutes ago, Alien10 said:

...

In your video, the bubbles are somewhat consistent in volume over the course of the video with the engine idling.  What happens if you raise the RPMs while watching the coolant in the radiator?   Do the bubbles increase in volume as you would expect if it is coming from a head gasket leak into the cooling system. 

This is more of a guess on what you've found so far, but maybe there is still a big air bubble somewhere in the cooling system that is slowly percolating up as the pump is pumping the coolant. 

 

 

I have checked. Can't be in two places at the same time. I'm good but not that good. LOL I'll have the put something on the gas pedal and watch. I didn't get the wife come out and hold the gas or anything. I'm afraid of what she would've hit with when I told her that the sxs was messed up. Riding around these side roads is about the only pleasure she gets. Doesn't say much about me does it. LOL 

There could be a bubble but not likely.

Just today I used a clamp. Clamped off the hose coming from the goose neck. Opened the bleed screw at goose neck. Just in case there was a bubble that way like you said. And the coolant still came out.

 

Got to laugh about it to keep from crying.

 

Was no coolant in the combustion chamber when I took out spark plug. The paper towel came out clean. I also disconnected the fuel pump and cranked and nothing came out while cranking.

I've got it running now with the ball valve for the heater off and the regular coolant hose on. So far all seem good 

No idiot light. The temp gauge say the the temp is good. Fan turn on at 175 and off at 165 according the gauge I installed on the radiator hose.

[Greg Kilgore]

1 hour ago, Joe Breaux said:

Look for tiny bubbles in the coolant recovery bottle while running and normal temp or hot.  Mine never got coolant in the oil but looked like Alka Seltzer in the recovery bottle.

I've got bubble coming up in the overflow bottle. Not Alka Seltzer. But I have got a steady 1/4 inch bubbles coming up about 2 bubbles a second.

[Greg Kilgore]

I can't mark any comment as the answer because both members that helped me diagnose this beast has provided the correct information to diagnose the issue. 

 

Thanks to both Alien10 and Joe Breaux for the help. With the information both provided I'm 100% sure there is a blown head gasket. The breach of gasket material seems to be between the coolant channel and the combustion chamber. Now all that remains is do I down the machine myself or take to shop. That is going to depend if I can get an enclosed place to work on this beast. LOL 

Thanks guys I appreciate the help.

[Joe Breaux]

18 hours ago, Greg Kilgore said:

I've got bubble coming up in the overflow bottle. Not Alka Seltzer. But I have got a steady 1/4 inch bubbles coming up about 2 bubbles a second.

That's a head or gasket leaking combustion gases into water jacket..

New gasket in you future..glad we could help..Now try to find a place to work. If you take it in, expect long wait  and big bill

[Greg Kilgore]

Side note. Did notice yesterday there was evidence of oil seeping to the outside around the head and block on the passenger side. All around the side to the back. 

Called a shop already. Closest shop to work on Hisun is 3hr away, 2 month waiting list and $500-$600. Didn't say how long it would take either.

So trying to find any shop closer to work on it.

I've replaced heads on simple 2.5 iron dukes in S-10 and 2.3 in rangers over the years. Rebuilt carbs, changed stators and did link and sync on outboards. All under a shade tree. But followed directions in repair manuals like Chilton's and Haynes.

Just don't have the space or shade tree now. It's cold outside here in Kentucky. And that sxs doesn't look like it's the easiest to get to all the engine that necessary. Without removing a lot of stuff. May just rip out the engine. So who knows if I'll tackle or the shop. 

If I tackle I'll be sure to take pics and post progress. Then there's the fun of finding parts and tools that are affordable. That's going to be fun.

Thanks again for the help.

[motojoe]

Sounds like you have an air bubble in the cooling system.  What you need to do is jack up the front of the side by side with the wheels off the ground and bleed the system and fill the radiator.,

[Greg Kilgore]

1 hour ago, motojoe said:

Sounds like you have an air bubble in the cooling system.  What you need to do is jack up the front of the side by side with the wheels off the ground and bleed the system and fill the radiator.,

I've pulled the beast up on 45° hill and bleed system. Even burping at the head. Believe me, I wish it was an air bubble. As much as I've have bleed the system, it's a blown head gasket between the coolant channel and the combustion chamber. But it never hurts to try again. 

[Alien10]

You could try to pressurize the combustion chamber with compressed air while at or near TDC (so valves are closed) to see if your bubbles still appear at the coolant filler neck. Try to keep the coolant tank opening as high as you can get it. 

By the way, you said the compression pressure went from 120 lbs to 105 lbs over 15 minutes.  Rings are not great at holding pressures for that long.  In fact my initial impression is that losing only 15lbs of pressure over 15 minutes is pretty remarkable.  Wonder if you repeated that compression test if you'd see bubbles in the coolant.  

Ah, maybe you're right, and the head gasket needs to be replaced.  Just trying to save you some heartbreak if that isn't the issue.

In any case, good luck, and please if you resolve this issue, let the forum know.  That's how we all learn. 

 

 

[Greg Kilgore]

I've been checking on shops that would work on this beast in the near future. So far I haven't had any luck.

I checked and there is one of those storage unit places that will allow me to rent a unit and work on the UTV there. Price isn't bad. 10x10 unit for $40 a month. As soon as he gets a spot open. LOL No electric, so I'll have to use my generator.

Parts, cylinder, piston, rings, wrist pen, gaskets etc will be about $300-$350 from Amazon or eBay. They have the parts for about $80-$100 for the older engine. But seems those only fit the 2015 and older. Mine is a 2021.

Still waiting on the right time and place to tackle this beast. With that said.

There isn't an auto parts store with the loan-a-tool around that has a combustion leak down tester to loan. Only 2 close by. Nor do they have the combustion gas detector either.

I checked on Amazon and can get the leak down tester for about $35. It has good reviews.

Can get the combustion gas detector fluid for $11 at harbor freight. Maybe parts store has the detector fluid. I haven't checked. But parts store doesn't have the bottle/tool to put the fluid in. But from what I've read. All that needs to be done is have the gasses pass through the liquid. So maybe I can rig something. Cause there are bubbles going into the overflow jug. Just remove that hose and place in an empty clear water bottle. And let it bubble up through some detector fluid.

Alien10, I don't have an air compressor or any way to apply pressure to the cylinder except with the compressor tool. The only air compressor I have is one of those 12v that you plug into a car cigarette lighter socket. My brother borrowed my 110 pancake air compressor 5 years ago. LOL I use battery impacts when I need a little extra ump on something.

As you suggested, I could put the compressor tester on. And use it to see if I have bubbles. That probably what I'll do today to get out of the house for a minute or two.  Maybe run to parts store also to see if I can get the gas tester fluid also.

Also just a FYI, on the driver's side of engine. Where the hose connects to the engine case. There is a hose that goes up to a type of air lock, a black plastic piece. That acts as a PCV valve. On the bottom of that piece are 2 nipples and 1 on top. The top has a hose that goes to the air filter box. So blow-by gasses don't enter the cab. One hose on bottom goes no where is is closed off at bottom. It's used to collect oil to keep it from dripping of machine/ground. The other connect to hose going to the case. That nipple is broken. Called an air oil separator, $15 on Amazon. So that is going to get ordered and installed soon. 

 

I'll keep everyone posted on the progress of this beast/issue. 

Wishing every one a Merry Christmas and a Happy Hangover.

 

Kilgore 

[Alien10]

Merry Christmas to you too.  Be confident, you can get this thing back in service.  Best of luck. 

[Greg Kilgore]

Thanks, Alien10, I need all the luck and confidence I can get. I'll get it one way or another.

Well a bit more confused now. I'll list what happened in order.

1. Opened the bleed screw on goose neck on top of cylinder. No antifreeze came out. Couldn't see antifreeze in hole. Screwed bleeder back on.

2. Opened radiator cap. Coolant was a little low. Topped it off. Left cap off.

3. Opened the bleed screw and left off until antifreeze came out.

4. Topped off radiator with coolant and put cap back on.

5. Made sure both of the ball valves were on. So coolant had a least resistance path through the engine.

6. Started engine and let it run for about 10 minutes. No smoke came out of muffler. Did have some "air" come out the hose that broke off the air oil separator. 

7. Removed spark plug, disconnected the coil and fuel pump. Installed the compression tester. Held gas pedal to the floor cranked the engine. Got 130psi. (Didn't do the pedal thing during the 1st testing). Lite a cigarette and started the stop watch on the phone. Listened and felt for air at muffler and air oil separator hose. Nothing. Raised the front of UTV about 6 inches. Removed radiator cap. There was a little pressure. But didn't see any bubbles. I drained the overflow jug back down to full mark. 

8. So 12 minutes has passed. Compression gauge is reading 125psi.

9. After 16 minutes, compression gauge is still 125psi. I bumped the engine in case the piston is in some way sealing the gasket that I think is compromised.

10. Watching the radiator, still no bubbles, after 20 minutes. Compression gauge is still at 125psi. Can't hear of feel any air at muffler or crank case hose. I release pressure on gauge. Hold gas WOT and crank engine. Compression gauge goes up to 125psi. Battery is weak. Drops to 10.5 while cranking and only 12.1 after.

11. After 30 minutes the compression gauge still at 125psi. Couldn't hear or feel or see air escaping anywhere. Radiator still topped off. No bubbles. Opened the bleed screw. Had coolant weeping around threads.

12. So now 40 minutes has passed from cranking the compression tester the 1st time today. Gauge still at 125psi. No bubbles, or anything. 

13. I release pressure from gauge. Removed gauge. Install spark plug. Reconnect coil and fuel pump. Left machine in air. Started machine. 

14. Let it run to get operating temp up. Variating the RPM from idle to 5k. Did get some blue smoke, but not a lot. Did have steady blow-by out the crank case hose, even with high RPM. Didn't see any bubbles in radiator. Put cap back on cause coolant started rising when engine temp started to rise. Didn't see any bubbles rising in the overflow jug. Loosen the bleed screw and no air came out. It just weeping coolant. Raised temp to about 150°. Still no bubbles in overflow tank.

15. Turned machine off. Left front end up in air. Will check everything again tomorrow, Sunday or Monday. 

 

At this point looks like there was/still some air in the coolant system. As motojoe, Alien10, and Joe Breaux has said all along. But I'm not 100% sure if head gasket is blown or just had air bubble. I'm going to raise the front some more. Then do the same testing and see what happens.

As the great Sweat-Hog, Vinnie Barbarino, once said, "I'm so confused."

I feel better now. 😂

[Joe Breaux]

Good luck..hope it's cured

[Alien10]

I might be misinterpreting the compression test results you've posted.  Wouldn't be the first thing I've screwed up this morning!   But, most if not all compression testers have a one way valve. That is to record the highest compression pressures it sees during the test.   It will leave the gauge at that highest level, even it there is no compression left in the engine's cylinder after it stops cranking,  until the release valve is pushed to release it back to zero.   I'm thinking that your 130 and 125 pressure readings, after being left for 15 to 20 minutes are just the pressure captured and retained by the gauge and hose?  Reason is I've never seen an engine cylinder that will retain 125 lbs of compression more than a dozen seconds as those peak pressures bleed down fairly rapidly through the rings. Those are by no means anywhere near a perfect seal. 

Your last results would seem to show a bubble was left in the system that you have now released.  Great detective work!  Maybe its time to just run the machine as you normally would paying attention to the temperature, coolant level and its appearance, and of course importantly, the oil level and its appearance.   If you have a head gasket issue, it will soon show up in the coolant or oil being compromised. 

 

[Greg Kilgore]

Alien10, 

Dude, I'm not blonde, but I never, never. Never thought or realized THERE IS NO WAY on GODS GREEN EARTH a cylinder would keep the pressure. My my my, I should hang up my tools, and just take up knitting. Any leaking has to come from the Schrader valves in the compression tester hose. I'm just doing a leak down test on the hose connection and hardware.

 

Alien10, thanks for explaining this. Making me realize what I was doing wasn't what I thought I was doing. 

Man, do I feel dumb. Some people shouldn't own tools. LOL guess I'm one. I'm a little (lot) embarrassed. But maybe others will learn from my mistake.

I'm still going to jack this beast up in the air and try the bleeding thing again.

 

 

 

[Joe Breaux]

Don't  feel bad. We have all done it. I recently. Had to replace a wheel on one of my Corvettes..It arrived in box, took it to tire shop, had the tire swapped over, balanced, installed on car..3 days later I realized...ITS A DIFFERENT WHEEL!...  duh...Vendor won't take it back because I mounted tire.. 

[Alien10]

Greg, no disrespect intended for sure.   Exactly how do you think I figured out how the compression tester's valve works?   The first one I had was used and with no instructions.  Thought it was broken.  Went to put it away and hit that little brass button hidden under the neck of the gauge,  and "PSSST ..." the gauge returned to zero!🤔

Don't be so hard on yourself, you're doing just fine!.  We've all been there and worse,.....in my case, a LOT worse.  Plenty of scars and a couple bits of missing flesh to show for it.   Guess I should be thankful to have survived 7 decades!   Wouldn't trade any of it including those most embarrassing moments for a million bucks. 

You're doing better than most, keep at it,  success awaits only those who keep on keepin' on. 

 

   

 

 

[Greg Kilgore]

Alien10

I didn't think any disrespect was implied or intended. I really didn't get offended in any way, shape, fashion or form. I REALLY did appreciate the education on the workings of the compression tester. And truly never thought about how it worked. And as a man that knows it all (joke intended), I didn't read the directions. Or didn't receive any. I've had this for 5 years. And either the directions never came with it or walked away.

And if I've offended anyone with the blonde comment, I truly apologize. Didn't mean to.  It's just a running joke between me and my wife. 

Anyway, all good. Thanks again.

 

[FireZingr]

Ack!! I've read all these comments and became so invested as I'm having the same issue with a 2022 Hisun 750 I need to know how this all played out?!?!?!?

 

[Greg Kilgore]

FireZingr, 

Yours will be different but for the 500 see below.

Well something about the engine I had. I couldn't get the $90 jug kit. I had to get the $350.00 ish kit from MotorCycleDoctor. But they shipped fast. All parts. Really recommend them.

 

Wasn't a real hard job. Took me a day to tear down. A day to put back together. And 3 hrs to get timing chain back on and in time. 

 

One reason it took so long was I lost a "C" clip on the piston wrist pin. Thought it dropped inside the engine. Looked for that thing for about 4 hours. Turns out it was under driver's seat. Also on old piston about 1/3 rd of the piston ring lip was broken. Didn't drop inside engine, just broken. Took off a few more items than I needed to. But it was all good.

 

Got everything thing back together. Gave it a real good burping and old change. Even changed the fuel injector cause it gave me issues before the head blew. Even replaced the spark plug. Reset the computer by the key switch on off cycling.  Think it cranked twice and fired up. Hasn't given any issues with engine since. Have put about 800 miles on it since the repair.

I did coat the head gasket with Indian Head and refused the big O ring off the old jug. Rest were all new. New jug, piston, wrist pin, gaskets, etc.

 

Old piston.

 

 

Old gasket. You can see the big O-Ring in this pic that I reused. It's on the outside of the cylinder ("sleeve?"). It's black and is under the gasket. If you look when the gasket meets the outside of the sleeve. You can see it if you look hard enough. 

 

New parts. Even came with new spark plug and crush gasket for exhaust. You can see the old O-Ring I reused under the new spark plug.

 

 

back together.

 

 

[Greg Kilgore]

Here are some pic of the timing marks

 

That was the absolutely hardest part  I put that bad boy together I'm guessing 100 times before I was satisfied. But in the end it paid off cause it was running after the 2nd turning over of engine.

The top pic was 99% complete. There's 2 stamped metal covers or something like that. That wasn't installed when I took the pic. They cover the timing marks on the top gear. And I wanted to rotate the engine a few times. That way I knew timing marks were correct. I installed before buttoning it all back up.

 

 

[Greg Kilgore]

Here is the diagrams I used and I watched a couple of YT videos.  The ones from the Hisun/Axis were junk. I will list the ones I watched in another post. Any links have to be approved by the admin. So it may take a minute before that post is up.

 

The numbers in the boxes with Nm after them is the torque specs. But I think I tighten the head bolts to 40Nm instead of the 38Nm listed. I reused all old fasteners.