Blown Headgasket or Bad T-stat
Sep 8, 2016, 01:25 PM
#16
Do a pressure test on the cooling system.. Also to check the thermostat feel the upper and lower hoses, they should be a similar temperature...
What kind of radiator are you running? Clogged radiator tubes could also do exactly what you're describing. You could also get a block tester, which sniffs for exhaust gas in the coolant.
What kind of radiator are you running? Clogged radiator tubes could also do exactly what you're describing. You could also get a block tester, which sniffs for exhaust gas in the coolant.
Sep 8, 2016, 01:36 PM
#17
Newbie
Thread Starter
sounds like headgasket to me.
pump vs e85, generally means more boost & timing on e85 = higher cylinder pressure when firing.
150psi during compression test vs 2600 - 2900psi when firing (180-200 bar cylinder pressure)
If your actually knocking, then that cylinder pressure not only goes up (20/40 bar spikes = 280/600 psi more), but the rate @ which the spike rises fck's you too.
so yeah, depending how bad the issue is, it may only manifest while on e85 & high boost or simply idling = your HG is FCKD.
pump vs e85, generally means more boost & timing on e85 = higher cylinder pressure when firing.
150psi during compression test vs 2600 - 2900psi when firing (180-200 bar cylinder pressure)
If your actually knocking, then that cylinder pressure not only goes up (20/40 bar spikes = 280/600 psi more), but the rate @ which the spike rises fck's you too.
so yeah, depending how bad the issue is, it may only manifest while on e85 & high boost or simply idling = your HG is FCKD.
Sep 8, 2016, 01:38 PM
#18
Newbie
Thread Starter
Do a pressure test on the cooling system.. Also to check the thermostat feel the upper and lower hoses, they should be a similar temperature...
What kind of radiator are you running? Clogged radiator tubes could also do exactly what you're describing. You could also get a block tester, which sniffs for exhaust gas in the coolant.
What kind of radiator are you running? Clogged radiator tubes could also do exactly what you're describing. You could also get a block tester, which sniffs for exhaust gas in the coolant.
Sep 8, 2016, 02:47 PM
#19
Newbie
Thread Starter
Do a pressure test on the cooling system.. Also to check the thermostat feel the upper and lower hoses, they should be a similar temperature...
What kind of radiator are you running? Clogged radiator tubes could also do exactly what you're describing. You could also get a block tester, which sniffs for exhaust gas in the coolant.
What kind of radiator are you running? Clogged radiator tubes could also do exactly what you're describing. You could also get a block tester, which sniffs for exhaust gas in the coolant.
Sep 8, 2016, 03:21 PM
#20
Evolved Member
Sep 9, 2016, 11:12 AM
#21
what were the outside air temps when you were running?
hopefully the t-stat decided not to open & caused your engine to get hot. swapping out a t-stat is easy to do, especially if you were going to the track again.
Sep 9, 2016, 05:44 PM
#22
The full overflow after coming off of the track sounds like my cart when I had a barely-blown HG. Basically like Barney described earlier; the HG would only leak under boost, so doing compression tests etc returned totally normal results. When the head came off, my shop showed me the block and you could see what path the compression gases were able to take to get to the cooling system.
That said, easier and much cheaper to test a thermostat than to go straight to a HG swap. I would start with testing the thermostat.
That said, easier and much cheaper to test a thermostat than to go straight to a HG swap. I would start with testing the thermostat.
The following users liked this post:
fugiwara (Apr 1, 2022)
Sep 10, 2016, 11:22 AM
#23
Newbie
Thread Starter
maybe it just took the time it did to blow out the coolant to a point where it began to overheat.....
what were the outside air temps when you were running?
hopefully the t-stat decided not to open & caused your engine to get hot. swapping out a t-stat is easy to do, especially if you were going to the track again.
what were the outside air temps when you were running?
hopefully the t-stat decided not to open & caused your engine to get hot. swapping out a t-stat is easy to do, especially if you were going to the track again.
Sep 10, 2016, 11:23 AM
#24
Newbie
Thread Starter
Do a pressure test on the cooling system.. Also to check the thermostat feel the upper and lower hoses, they should be a similar temperature...
What kind of radiator are you running? Clogged radiator tubes could also do exactly what you're describing. You could also get a block tester, which sniffs for exhaust gas in the coolant.
What kind of radiator are you running? Clogged radiator tubes could also do exactly what you're describing. You could also get a block tester, which sniffs for exhaust gas in the coolant.
Sep 10, 2016, 11:53 AM
#25
Newbie
Thread Starter
The full overflow after coming off of the track sounds like my cart when I had a barely-blown HG. Basically like Barney described earlier; the HG would only leak under boost, so doing compression tests etc returned totally normal results. When the head came off, my shop showed me the block and you could see what path the compression gases were able to take to get to the cooling system.
That said, easier and much cheaper to test a thermostat than to go straight to a HG swap. I would start with testing the thermostat.
That said, easier and much cheaper to test a thermostat than to go straight to a HG swap. I would start with testing the thermostat.
Sep 11, 2016, 05:01 PM
#26
Evolved Member
If the problem persists and you are still on stock head bolts, I'm thinking you might try the one at a time ARP stud replacements. It might work and if it doesn't you still have the hardware for later.
The following users liked this post:
ShanesEVO (Sep 14, 2016)
May 17, 2017, 02:39 AM
#27
Newbie
Join Date: May 2017
Location: England
Posts: 3
Likes: 0
Received 0 Likes
on
0 Posts
Ok late to the party here but for others who might find this thread.
Not on an Evo but I had similar issues. Every 300 miles or so would loose enough water for heaters to blow cold. No signs of white smoke etc etc or water in oil.
What I done to prove was pressure test the coolant system by using a bike pump. Took the system to 1.3 bar and looked at pressure gauge on pump. First couple of times found minor leaks over an 8 hour period. When I finally was leak free, left for a week and pulled the plugs. Found about 5 drops of coolant on the top of one of the pistons. Now proceed to do the same test with valves closed on suspect cylinder. If no leak then you can go for exhaust closed/ inlet open to find where your crack is (either inlet or exhaust jacket). If it still appears with both valves closed then you have tracking from coolant jacket to combustion chamber.
For me I was lucky (hopefully) found two of the ARPs where not tightened to spec (standard spec) and the rest not to spec for MLS gasket. So far so good not had re-occurance. Hope this helps someone else. How did the OP get on what was the fix?
Not on an Evo but I had similar issues. Every 300 miles or so would loose enough water for heaters to blow cold. No signs of white smoke etc etc or water in oil.
What I done to prove was pressure test the coolant system by using a bike pump. Took the system to 1.3 bar and looked at pressure gauge on pump. First couple of times found minor leaks over an 8 hour period. When I finally was leak free, left for a week and pulled the plugs. Found about 5 drops of coolant on the top of one of the pistons. Now proceed to do the same test with valves closed on suspect cylinder. If no leak then you can go for exhaust closed/ inlet open to find where your crack is (either inlet or exhaust jacket). If it still appears with both valves closed then you have tracking from coolant jacket to combustion chamber.
For me I was lucky (hopefully) found two of the ARPs where not tightened to spec (standard spec) and the rest not to spec for MLS gasket. So far so good not had re-occurance. Hope this helps someone else. How did the OP get on what was the fix?
Last edited by scoobydo; May 17, 2017 at 02:41 AM. Reason: Paragraphs
May 17, 2017, 05:50 AM
#28
block tester didn't show my failed head gasket- the fluid also stayed blue. there were not gasses in the coolant present when I was testing it. otherwise, the symptoms were identical. it eventually go worse to where a very long drive on the freeway would pressurize the system and push coolant out of the overflow.
May 17, 2017, 07:47 PM
#30
Newbie
Thread Starter
I ended up taking it to a local evo shop. They did a cylinder leak down test, everything looked good according to them. The tech that did it said that my head studs were stretching. They were replaced with ARP head studs, haven't had issues since.