Pressure testing for head gasket leak

[Mooney 2]

Any mods or recent work on the sled? When you say it overheats what is the actual coolant temperature at that point? Also, have you seen the fan run?

After a heat cycle and coolant fills the overflow bottle can you add coolant to the radiator? If so add it but only when cold. Run it again until the coolant temperature increases enough to open the thermostat and circulate the coolant then let it cool again and recheck to see if you can add coolant to radiator when cold. Do this several times and if there is a problem the added coolant will eventually fill the overflow bottle to the point it overflows.

No mods completey stock

 

[scalise71]

My apologies, I read it wrong.

 

[yammitrip1]

Didn't pressure test to find head gasket leak, tested to find any other leak.

I was reading the head line of the thread, then responded. My bad! Have you found any issues yet?

I have never heard of this on one of these engines but a bad water pump will cause similar head gasket issues

 

[yammitrip1]

Does the engine hold pressure sitting over night??

 

[grizztracks]

It to my knowledge has never had a turbo. Just to clarify. Tonight we vacuum filled the system and it seemed to have air in it. It took three bleeds to get all the air out. Idled in the shop for 20 minutes operating properly up to 195 fan comes on cools to 183 fan shuts off over and over. Went for a ride at fairly high speeds with some wot runs. Come back after 15 mile loop and the overflow bottle is near full again from starting at half. Let it cool to see if it would suck some back in after cooling, nope. Went out again on a bit shorter loop and it pushed more coolant to the bottle to absolutely full. Gonna do a leak down test next but im pretty sure its a head gasket. Shitty!

I agree that there's a good chance the head gasket needs replaced. I haven't had to do one in a Viper yet but have done several in the Nytro. Like I said, there have also been reports of the vein in these water pumps breaking so it might be worth taking a look.

 

[grizztracks]

There is a method of testing using a pressure gauge. If you did a pressure test the tester used should have a gauge. It can be used to read the pressure in the system from cold start to hot. The only increase in pressure is due to the expansion of the coolant so if there is a rapid increase in pressure before you're up to operating temperature it's probably due to compression gas leaking into the system. Be careful doing this because there is no pressure relief and pressure can increase beyond your gauge and what the radiator or hoses can take fairly quickly when a head gasket problem is present.

 

[Mooney 2]

What are you guys seeing for normal temps ? My experience so far is at cruising speed it runs between 165 and 170 however the temp climbs quickly when stopped, like at a road crossing if you have to wait a minute for cars it gets up to 195 pretty quick. When the system has been filled it cools again once you start rolling again. Is that normal operation for these sleds? After it pushes coolant into the overflow it doesn't cool but just trying to figure out what is the norm on theses machines when operating properly. Thanks for you all for the information to this point, I appreciate it.

 

[grizztracks]

 

[grizztracks]

It's important to know the engine will not shut down when overheating unless it's at idle and if coolant is lost there is nothing for the temperature sensor to read so the engine can overheat without the condition being detected.

 

[Mooney 2]

It only seems to overheat once it has pushed out Enough coolant to make the system low. It doesnt over heat and push fluid out, it just pushes fluid out to the point it then overheats.

 

[Mooney 2]

We have done a pressure test, fine. Changed thermo sensor. Tested thermostat, fine. Tested rad cap and it blows off at 16psi like it should. Did the blue fluid check for combustion gasses in the coolant, no change in fluid color. Vacuum filled system, took three trys but got all air out. Gonna check water pump next then a leak down test. This #*$&@ is getting old fast! About wore out all the shitty fasteners holding the hood on. Not impressed so far.

 

[cannondale27]

What are you guys seeing for normal temps ? My experience so far is at cruising speed it runs between 165 and 170 however the temp climbs quickly when stopped, like at a road crossing if you have to wait a minute for cars it gets up to 195 pretty quick. When the system has been filled it cools again once you start rolling again. Is that normal operation for these sleds? After it pushes coolant into the overflow it doesn't cool but just trying to figure out what is the norm on theses machines when operating properly. Thanks for you all for the information to this point, I appreciate it.

This is normal.

 

[Mooney 2]

UPDATE. So by the next morning it did actually suck coolant back from the overflow which it has never done before. Good sign! So I sucked a bit out of the overflow bottle to get it back to full cold line. ( didn't have to take much out) went for a ride again. No overheat ran fine get back and it has pushed some back in the bottle but not much. After cooling it again sucked coolant back in to get back to full cold line. Seems everything is good and it was an air lock. Went for a ride this afternoon and after pulling over to drain the lizard starts getting hot, get rolling and it's not cooling like it was. Overheats and takes awhile to get home letting it cool every mile or two. Thinking it's still a serious issue. Get home take hood off and the rad is full of cotton. Must have hit a cat tail when I pulled off trail (didn't see one but I got the whole thing in the rad) . Cleaned it out and went out again seems ok. I can't believe this ! An air lock has been tormenting me since December and the day I think I got it handled I hit the biggest cat tail dead center with the rad. I have more grey hair ! But I think it's finally corrected. In all my years I have never had to vacuum fill a cooling system. Guess there is a first for everything. Anyone ever found a frog skin for the rad opening on the hood of these things?