GTX260 iS limited Coolant leak and oil light on limpmode

[jaydamuss]

I have just purchased this with a coolant leak, I have pressure tested coolant and seems fine, Took it out on the lake today and it ran fine for 5min. Then returned to the shore and checked the coolant. Coolant was all around the expantion tank, I topped it back up a tried again it seemed fine going slow until I opened it up 80km for 15sec before the temp up and oil light came on, and it went into limp mode. Again, I went back to the shore and water was bubbling out of expantion tank. I topped it up and since then the oil light comes on, but only when you rev to 2000 or more, it idles fine. A couple of times I turned it off and on and it worked fine again and then took for a medium speed run and coolant and oil was fine.
I am wondering if the oil light is on due to temp of oil because water temp went up (low water) and oil cooler could not cool or is this a completely seperate issue to coolant leak?
I am thinking of replacing thermostat as maybe its stuck and causing coolant over pressure and leak out of expantion tank?
Would I be on the right track?, any help appreciated. Cheers

 

[jaydamuss]

I repaced water pump gasket and thermostat and tested out on lake
still uses water when going above 6500rpm under that and temp is fine and water fine, i am thinking its head gasket now (will try the coke bottle test on overflow pipe next time on lake)
i also replaced oil pressure switch and it fixed limp mode and oil light.

 

[dcm0123]

How is the overflow tank pressure cap?
Any signs of water in the oil?

 

[jaydamuss]

I have replace the cap with a new one which didnt change anything, The overflow tank looks clean no signs of any oil, this was main reason i thought it was thermostat

 

[200mph]

Have you done a leakdown test? Notice any bubbles in coolant when doing test?

How long did you run the coolant pressure test and was there any pressure drop from start to finish?

The thermostat could be removed and tested in a pot of water using a candy thermometer to verify when it opens. Prefer to know it’s condition versus just swapping out.

They also sell a coolant tester for head gasket leaks. A chemical is used that interacts with combustion chamber gases. Harbor freight and many other places sell it.

Example: Amazon.com

 

[dcm0123]

I would not expect to find oil in the overflow tank but you may find combustion residue in the coolant which would show up on the test 200mph mentioned above.

Water can end up in the oil if it seeps past the piston rings.

I have a 2005 and they said to refill the coolant you need to pull the plug on the ride plate under the the impeller housing while filling to bleed out the air. Is yours the same set up and did you follow this? You may have trapped air in your system.

 

[jaydamuss]

Have you done a leakdown test? Notice any bubbles in coolant when doing test?

How long did you run the coolant pressure test and was there any pressure drop from start to finish?

The thermostat could be removed and tested in a pot of water using a candy thermometer to verify when it opens. Prefer to know it’s condition versus just swapping out.

They also sell a coolant tester for head gasket leaks. A chemical is used that interacts with combustion chamber gases. Harbor freight and many other places sell it.

Example: Amazon.com

I have done a leak test to 13 and it lost 2 over 15min, i replaced thermostat as i put both in boiling water and new one opened wide the old one only half opened so i replaced thinking it was a sticky thermostat. i have ordered the chemical test and will find out when it arrives

 

[jaydamuss]

I would not expect to find oil in the overflow tank but you may find combustion residue in the coolant which would show up on the test 200mph mentioned above.

Water can end up in the oil if it seeps past the piston rings.

I have a 2005 and they said to refill the coolant you need to pull the plug on the ride plate under the the impeller housing while filling to bleed out the air. Is yours the same set up and did you follow this? You may have trapped air in your system.

yeah no oil but it does seem to have very small (and not much) traces of black stuff. yes we have to undo the allen key and bleed aswell

 

[200mph]

"I have done a leak test to 13 and it lost 2 over 15min"

Not the type of leak down test I was referring to, but thanks for proving the info. That's a pretty good drop.

The test I was refereeing to is a substitute for a compression test. It's usually more informative than a compression test.

 

[dcm0123]

If you have a spark plug compression tester which can be connected to an air compressor hose, it will also work well.

Bring the piston up to TDC to close the valves and apply 100 PSI air pressure.

Keep the cover off your coolant tank and look for air bubbles. Will be a lot if you have a leak into the cylinder where they usually leak.

 

[jaydamuss]

Unfortunately i dont have compression tester or compressor, hopfully the chemical test would be enough

 

[200mph]

Fyi… Advance auto or similar have a tool rental program. Requires a down payment to rent, which is refunded when tool isreturned, thus free.

 

[jaydamuss]

Ok i have purchased a compressor and a leak down tester. is there an easy way to turn engine over to get TDP cheers

 

[dcm0123]

Only way I know is by turning the output shaft.
Use a long screw driver through the spark plug hole to find TDC.

 

[jaydamuss]

Ok removed head and got it tested, and was warped and exhaust valves were not seated. Got head recond and replaced wear ring and fitted stainless impeller and tested out on water with no issues anymore, 115km and temp 84c