Trackday overheating

[Grid]

Today's trackday was a bit of a disaster. Hot day - 30C. After 15 minutes on the track the engine severely overheated - I first noticed that the autobox was blinking an error code at me, then my gaze shifted to a check engine light, finally to the temperature indicator hovering as high as it can go above the H mark. Snap. Return to pits, asess damage. And the day barely started!

First thing I noticed - the overflow reservoir was empty, I put some coolant in it but it started doing something which didn't strike me as normal. See video, with engine off:

https://www.youtube.com/watch?v=flez2kEYPSI

So I let the car sit for 15 minutes to cool down so that I can check the radiator cap - unscrewed it and saw... a dry radiator. Snap. Snap. Then I notice a spring lying on top of radiator, and the fact that the radiator cap was missing parts. Triple Snap.

So I found a new cap - 1.1bar, refilled system and drove on. But still I was getting the occasional spikes in temperature. Not "H" level though, but half way, at which point I was making cooling laps.

What I am guessing has happened is that the system got up to temperature and pressure, and the radiator cap broke down due to age. Then coolant got pushed out... Not sure how all of it managed to escape though? I think I used 5-6l of coolant to refill the system at a gas station.

[foxdie]

Looks like it boiled itself dry :(

I'd keep a very close eye on compression and the cylinder head now, there's a small chance you may have damaged the head.

Hows the oil level?

Might wanna look at aftermarket cooling too, with pushing our turbos further (I know we have) that'll naturally ramp up temperatures so I'd also look at an oil cooler too. Maybe with a remote sandwich plate.

[Grid]

Looks like it boiled itself dry :(

I'd keep a very close eye on compression and the cylinder head now, there's a small chance you may have damaged the head.

Hows the oil level?

Might wanna look at aftermarket cooling too, with pushing our turbos further (I know we have) that'll naturally ramp up temperatures so I'd also look at an oil cooler too. Maybe with a remote sandwich plate.

Checked oil this morning and level is OK. I'll plan a compression test in the future, I never did one. I have a feeling the system was not bled properly and that is why the system overheated Sunday. I need to add a UTComp warning for coolant and oil temp.

[Davezj]

If you do a compression test and it shows a leak, do a leak down test and it will tell you where the leak is occurring, inlet valve, exhaust valve, head gasket, or piston rings.

Just search for leak down test on YouTube to find out what it is if you don't know.


Sent from my space-aged gizmo

[crazydriver81]

What a mess Tomasz! As others suggested, make a compression test. If you lost 5-6l then this is basically all coolant. Did you fill up with water or coolant? If just plain water, you need to change for proper coolant immediately, to avoid block corroding inside.

The only explanation I have for this huge leak is failing of the rad cap, thus leading to no pressure on the whole system and let the coolant boil easily (and escape via overflow tank).

You definitely need to check temp sender status (2-pin, on top of thermostat housing). They often get tired and switch on the fans too late.

Last but not least a proper alloy radiator will be needed as well.

Good luck and fingers crossed there is no major damage to your engine!!!

[Nick Mann]

Are you running increased boost? On a hot day maybe even standard boost is enough though.
I always get temperature spikes after 15 mins on track, even on cool days. I think that the coolant can't take enough heat from the oil when driving hard and after a while the oil gets so hot that the coolant starts heating up too. I have not got an oil temperature sensor so cannot be certain but I certainly intend to fit an oil cooler at some point.

[SEAN-NZ]

Oil in mine gets up to 120 pretty quickly when I go for 200kph, running about 1 bar of boost, coolant doesn't get any hotter with the alloy rad though


Sent from my iPhone using Tapatalk

[Grid]

Are you running increased boost? On a hot day maybe even standard boost is enough though.
I always get temperature spikes after 15 mins on track, even on cool days. I think that the coolant can't take enough heat from the oil when driving hard and after a while the oil gets so hot that the coolant starts heating up too. I have not got an oil temperature sensor so cannot be certain but I certainly intend to fit an oil cooler at some point.

Slightly increased boost, yes - peaks to 0.9 bar when pushed. I have sensors for oil temp and pressure, but never found any time to connect them, seems now is the time to do that. Also UTComp has some basic logging features, could come in handy.
crazydriver81 - I used proper coolant to refill system. The rad cap suffered a complete failure, so I am convinced that is how the coolant escaped. I'll check the sender, maybe even hook it up to UTComp while I am at it.

[swinks]

Gutted...
I hope you didn't refill system with cold coolant just after discovery, and let the engine cool down itself. Pouring cold coolant into overheated engine is just making micro cracks in head due to heat shock.

Hope it's all good.
Now you and others have lesson why oil temp and pressure gauges are necessary :)

[Grid]

Gutted...
I hope you didn't refill system with cold coolant just after discovery, and let the engine cool down itself. Pouring cold coolant into overheated engine is just making micro cracks in head due to heat shock.


Car was stationary for 15-20 minutes before I dared put coolant in, and even then I did it slowly. First through the overflow reservoir (which is when it did the dance) then after 30 mins downtime through cap into the radiator. I hope I managed to mitigate the worst of it. A compression test should verify.

[Grid]

An update to this thread. The compression test came back fine and I drove the VR-4 almost daily for the next 10 months. I did notice the coolant levels were not quite right, and that the overflow bottle was always topped after a good blast. The plastic bottle test revealed that significant amounts of coolant were pushed out of the overflow when gunning it.

Last weekend I went to a trackday, and lo and behold - same behaviour, 3 laps down the track, lost 3l of coolant, engine on the verge of overheating. Since I was expecting it I pulled over and refilled the rad. Situation repeated itself within the next 3 laps, so my trackday was a lost cause and the mystery remains.

I do not have the typical symptoms of headgasket failure. Exhaust is only white when starting up from a cold engine. No bubbles in the coolant, no oil in coolant, no water in oil. So it must be something else. Engine does not overheat when daily driving, when 1/4 of coolant got pushed out the remaining 3/4 stays in and does the job.

Read a post by veegeeta where he claims that he had clogged water passages in the head and block due to an unknown cause, possibly water hose lining separating. I am suspecting something similar in my VR-4. What would you advise I do short of taking the engine apart. I will replace the water hoses and possibly the radiator, but can I eg. run pressure water through the engine block in reverse to try and unclog it?

Oh and, there seems to be something wrong indeed with my water hoses - lots of black carbon particles in my coolant.
77397
77398

[adaxo]

Search here, if you didn't already :-) 'head lift' it can occur on 'blast' and be perfectly fine in 'daily' use

[Grid]

I'll search for it... learn something new every day

[Davezj]

this is what i believe my car is suffering from

on a daily run to work no problems but go for a thrash and the engine will blow out 2-3L of collant out of the rad overflow tank.
if after you go for a thrash in the car you see bubble in the over flow tank then use a sniff tester for hydrocarbons (exhaust gases) in the coolant. mine came back as a positive result for exhaust gases in the coolant system.
this is a head gasket issue for me. if you have standard head bolts like me it is likely the head bolts have streached.

i believe the head bolts have streached under increased pressure from higher boost and they now give every time i thrash it.

the fix would be new head gasket and new NO streach bolts or studs for me.

[Grid]

Yup. Had a chat with veegeeta - well cleaning the water passages in the head also entails taking the heads off, so new headgaskets. One way or the other - this is the path forward. I'll do the ARP studs at the same time.

[crazydriver81]

We have a car in the workshop right now, with exactly the same issue. When driving on the motorway at higher sppeeds for longer time, coolant gets pushed out via overflow tank. The owner lost up to 3l once. When driving the car normally nothing happens. Not even slight bubbling or whatsoever. And yeah, when coolant is pushed out via Overflow tank, the tester showed exhaust gasses too.

Stripped down the engine and gave the heads to a specialist for pressure/leak testing and cleaning, as well as probably skimming the heads. Heads came back today and had to be skimmed (possible cause: lost too much coolant so that the heads were not cooled anymore).

Upon closer inspection of the block and the head gasket no obvious leaks could be found. There were some slight marks of a possible coolant leak on cyl #5 but thats about it.

One thing we definitely noticed was, that the head bolts were not very tight when we loosened them. This would at least narrow the head lift theory.

There is only one question to me - would it be possible to re-tighten the head bolts? They are easily accessible when rocker covers are off but would it be possible or help (not in our case but generally)?

[swinks]

Head lift happens quite often with Evo 4 and 5 if you read MLR forum. Apparently vehicles build between 1995 and 1999 suffer the most, due to manufacture process and ageing. Folks from MLR used to re-torque bolts if issue is not too dramatic, but too much lift may lead to surface wrap.
So thinking out loud, that issue may occur more often now with vr4 community ;)

[Davezj]

We have a car in the workshop right now, with exactly the same issue. When driving on the motorway at higher sppeeds for longer time, coolant gets pushed out via overflow tank. The owner lost up to 3l once. When driving the car normally nothing happens. Not even slight bubbling or whatsoever. And yeah, when coolant is pushed out via Overflow tank, the tester showed exhaust gasses too.

Stripped down the engine and gave the heads to a specialist for pressure/leak testing and cleaning, as well as probably skimming the heads. Heads came back today and had to be skimmed (possible cause: lost too much coolant so that the heads were not cooled anymore).

Upon closer inspection of the block and the head gasket no obvious leaks could be found. There were some slight marks of a possible coolant leak on cyl #5 but thats about it.

One thing we definitely noticed was, that the head bolts were not very tight when we loosened them. This would at least narrow the head lift theory.

There is only one question to me - would it be possible to re-tighten the head bolts? They are easily accessible when rocker covers are off but would it be possible or help (not in our case but generally)?
The factory head bolt are streach type and a length tolerance on the in the Mitsi workshop manual I think it is not greater than 96.4mm long. The head bolt streach during the torque up process anyway.
So if the bolt is less than that it can be reused.
However if you experience head lift the head gasket is probably damaged by the gasses blow past it into the coolant system and the longer it is left the worse the damage will be.
So as a temp fix you could undo each bolt one at a time remove it check the legnth re torque it to the factory values. Or just risk it and re torque each bolt in turn. I don't think this will do any harm but it will only be a temp fix until you can race the head gaskets and preferably replace the factory streach head bolt with NO STREACH bolts or studs.
By the way head bolts are m10 with 1.25 pitch (fine pitch).



Sent from my MI 5s using Tapatalk

[Davezj]

We have a car in the workshop right now, with exactly the same issue. When driving on the motorway at higher sppeeds for longer time, coolant gets pushed out via overflow tank. The owner lost up to 3l once. When driving the car normally nothing happens. Not even slight bubbling or whatsoever. And yeah, when coolant is pushed out via Overflow tank, the tester showed exhaust gasses too.

Stripped down the engine and gave the heads to a specialist for pressure/leak testing and cleaning, as well as probably skimming the heads. Heads came back today and had to be skimmed (possible cause: lost too much coolant so that the heads were not cooled anymore).

Upon closer inspection of the block and the head gasket no obvious leaks could be found. There were some slight marks of a possible coolant leak on cyl #5 but thats about it.

One thing we definitely noticed was, that the head bolts were not very tight when we loosened them. This would at least narrow the head lift theory.

There is only one question to me - would it be possible to re-tighten the head bolts? They are easily accessible when rocker covers are off but would it be possible or help (not in our case but generally)?
By the way did you get any pictures of where the head gasket leaks. I think it will be a similar place for most people I have seen other threads where people say they will post pictures and do a round up of their finding but this never seems to happen.
Crazydriver81

Sent from my MI 5s using Tapatalk

[Davezj]

Head lift happens quite often with Evo 4 and 5 if you read MLR forum. Apparently vehicles build between 1995 and 1999 suffer the most, due to manufacture process and ageing. Folks from MLR used to re-torque bolts if issue is not too dramatic, but too much lift may lead to surface wrap.
So thinking out loud, that issue may occur more often now with vr4 community ;)
That is interesting to know that the 4g63 engine suffers from the same issue.



Sent from my MI 5s using Tapatalk

[crazydriver81]

By the way did you get any pictures of where the head gasket leaks. Crazydriver81

Sent from my MI 5s using Tapatalk

That was Kind of a disappointment as we have not found clear marks of where the gasket might have leaked. The bolts on the rear bank have been very loose compared to what force is needed when tightening the heads.

Only one cylinder showed minimal signs of having a coolant leak (cyl #5). Fact is that both sides of th gasket have been covered in a black mixture of something which was very hard to remove. Heads have been skimmed anyway but removing that crap from the block side was a nightmare (greasy, sticky whatsoever).

I have a few Pictures on the phone which I have to upload.

One last remark on re-tightening the head bolts. accordinf to the Workshop Manual, there is no defined force (Nm) defined for the head bolts. They rather define it in tightening them with a defined angle (20Nm + 2x 120°). So if you re-tighten used bolts it is either to loose or you risk to snap the bolt

[Davezj]

Thanks for the update.
It is a shame there is no obvious leak point. But it is odd that the head gasket was covered in black gunk that is not the normal way these head gaskets are fitted from the factory. Which leads me to think your heads have been taken off in the past. Possibly for the same reason, which is why the used the black gunk to try a seal the possible leak into the cooling systems.
What might have happened is they refitted the head and forgot to re torque the head bolts free a few heat cycles.
Or could not be bothered due to faff with removing the plenum chamber to do it.

The method of tightening the head bolts in the manual is specifically designed for stretch bolts. It streches the bolt. And the manual says if the bolt is less than the specified length then they can be used again.
Personally I would not bother using them again as I can get 8 bolts for about £20. Don't go to Mitsi dealer for them they cost a fortune.
But you can re use them according to the manual.

Sent from my MI 5s using Tapatalk

[Davezj]

Buy the way crazydriver81​ where have you uploaded the pics to?

Sent from my MI 5s using Tapatalk

[crazydriver81]

Buy the way crazydriver81​ where have you uploaded the pics to?

Sent from my MI 5s using Tapatalk


Here you go Davezj. Pctures were still on my phone. :D

I personally can't imagine that someone should have used material to reuse the gaskets. I don't know of any material that would be able to handle pressure and temperature in that area of an engine, but I could be wrong. Anyhow, now it's back to factory specs and we also used all new OEM bolts.

The closeup picture is cyl #5 and it shows some signs of coolant have been burnt.

Anyhow, I just can repeat the car only had the problem when being driven in higher rev ranges (etc. 160 kph on the motorway for longer). On constant 120kph driving that would not occur. When coolant was pushed out via overflow bottle, combustion gasses have been detected very clearly there.

So the failure in this case has definitely to do with pressure and revolutions which, together with the relatively loose head bolts on the rear bank, lead to the conclusion that head bolts might have stretched over time and made the head lift. However, it might have lead to a complete failure of the gasket in the future.

77405774167741577414774137741277411774107740977408 774077740677417

[Davezj]

Thank for the pics they are I interesting.
Possibly The black gunk on the top of block could be the surface finish of the head gasket being baked on to the block as that is a black colour.
But it is only a guess.
Thank again for the pics most appreciated.



Sent from my MI 5s using Tapatalk

[crazydriver81]

DavezjGrid

Car has been put back together and on the road. All fine again, no issues anymore with the engine. The guy had a 200km drive with 160kph on the way home and no boiling, pushing out water etc. Boost kicks in as expected (car had a loss of top boost by 0.15bar before!)

Work carried out:
new OEM head gaskets and OEM bolts
heads leak tested
heads skimmed

So, to my understanding clear signs of head lift issues are:
- no oil in coolant / no coolant in oil
- pushing out excessive amount of coolant through overflow bottle and boiling coolant
- loss of boost
- exhaust gasses detectable in coolant (and coolant smells like fuel)

[Davezj]

Excellent round up.
Thanks for the info.
If you remember can you do. Another update in a couple of weeks time. Even if it is just a "everything still fine".

It would be much appreciated.

Sent from my MI 5s using Tapatalk

[Grid]

Very cool! Thanks for sharing. My mechanic thinks he can do the heads and studs without taking the engine out... interesting to see if he manages that.

[Davezj]

I would imagine you can put the heads in place with the gaskets then fit the studs. But if you try and remove the heads after the studs have been fitted the rear head will probably not come off as it might hit the firewall/engine bay bulkhead.
Not that you would want to be taking the heads off again any time soon.
Hopefully it will be the last time you will need to.

I too am hoping to do the head gaskets without removing the engine . So I hope your mechanic can do it.
Maybe the head manifold and turbo can come out as one item from the rear. I am not sure if this is possible. I don't even know if it is possible for the front head with the radiator removed can be taken off in one go

I will listen out for any updates.

Sent from my MI 5s using Tapatalk

[crazydriver81]

I just can emphasize that taking the engine out will make your job a lot easier and faster. We take the engine out inc subframe and gearbox etc.

Take out part of propshaft, remove engine crossmember. Remove downpipes, take out driveshaft from wheel hub, remove steering column from steering rack and disconnect the from suspension linkage from the the subframe basically. Of course take out radiator before, disconnect cables and power steering lines.

Then remove the nuts holding the subframe, putting a pallet underneath and finally disconnect engine and gearbox mount and then you can lift the car and engine is out. Engine in and out is a 1 hour procedure each and worth IMO

[Grid]

Very cool! Thanks for sharing. My mechanic thinks he can do the heads and studs without taking the engine out... interesting to see if he manages that.

That statement lasted for all of about 15 minutes :D

Engine is getting put back together now. I am also doing a twin TD04 conversion because why not.

77969

[Nick Mann]

Awesome!

[adaxo]

Cool, please let know your welder there will be demand for TD04 manifolds here in uk, it will be great if we eventually can get them.

[Grid]

A small update here. The car is out on the streets with the twin-TD04's and the rebuilt engine with stronger head studs. So far so good - absolutely no coolant loss whatsoever even when gunning it. And it goes like stink! Need to tweak the fueling and then get a dyno sheet for posterity's sake...

[Nick Mann]

Awesome!