S/V/C Coolant bottle not holding coolant on V70 T5

So at least from my pov, it doesnt seem very common for someone to post about a v70 on here but im well aware that people know alot about the whiteblocks.

So heres my situation...

So recently me and a buddy of mines did an engine change on a 1999 V70 T5 to a lower mileage engine and most of everything was perfectly fine besides a few leaks just from some stuff we ended up forgetting to tighten. So the issue now after we tightened every visable leak is that it seems like the engine is overpressurizing the coolant bottle and forcing coolant out the cap.

After finding this out, we decided to troubleshoot and get rid of some variables...

-We changed the actual bottle and swapped a cap on that we were sure works.

-We replaced most if not all lines leading from the bottle even though we were sure these werent the issue.

Then we proceeded to assume its a headgasket

So we know that sometimes a car wouldnt show any symptoms of this while having this problem but the issue we are hitting is that if it did have the issue, after all this time weve driven it we would assume itd at least get noticibly worse but we havent had any of those at all.

So far the only "symptom" were finding is the problem were trying to fix. We even checked all the plugs and ports for any signs of coolant, checked for consistency among the plugs and we found nothing wrong.

We are pretty much stumped at this point considering how much weve replaced revolving around the problem. From what were finding, there shouldnt be anything wrong unless were completely oblivious to something...

SO Question now is, does anyone at all know what problem were having or have any experience with this cause were out of options here as we feel like we have tried everything. This was made the car quite irritating to drive since it drains specifically its bottle every 20 to 30 minutes or so and this is the last leak.

Feel free to ask any questions if i didnt seem thourough enough with the issue, i'm kinda rushing typing this.

Oil in water? Water in oil?

Pressure test cooling system for real leaks.

Thermostat?

From what were seeing, there doesnt seem to be oil in the coolant or coolant in the oil and weve pressure tested the system a few times now and havent found anything other than that. The coolant just simply seems to be expelling itself out of the reservoir cap.

We kinda thought of it somehow being the thermostat but were unsure of how the thermostat would cause this issue. Feel free to enlighten me, I need to learn haha.

but besides that, weve checked everything, we have little to no symptoms of a headgasket but still have this ongoing problem. The headgasket is kinda the biggest thing we want to avoid having to fix considering one of the main motivations for swapping a lower mileage engine in was because the old 260k+ engine blew its gasket catrastrophically.

My bad for not mentioning the oil and coolant mixture checking stuff.

Sorry, head gasket most likely. You obviously have too much pressure in system.

Any signs of engine over heating? Got a IR thermostat? Thermostat or a clogged radiator could cause over heating and high pressure.

I don't actually have a IR thermostat but I do know via obd2 reader, that the engine usually runs around 210-220 average when fully warmed up. I'm not quite sure what the normal average for a whiteblock is though.

I guess even if it is the headgasket, it wouldn't hurt getting a new thermostat and checking the radiator thoroughly.

Adding on to this, another thing we did change was us deleting the heater system due to a seal leak in the firewall. We connected the sending and returning line together to bypass that problem temporarily, I'm not quite sure if that could cause any issues there but I'm assuming not.

You probably have a 180 or 190* thermostat so the engine should run only a few degrees above that. Stuck in traffic on a hot day maybe the 210*.

Sounds like it could be a very slight HG leak issue, where combustion gasses can force their way into the cooling system only under stress, but coolant isn't able to leak the other way, and oil and water aren't mixing.

Get a bottle of this stuff to verify: http://www.autozone.com/test-scan-a...st-kit/oem-block-tester-test-fluid/391381_0_0

Worthwhile double checking before tearing the engine apart.

I've had Cometic's fail on me twice in a very subtle fashion. They even comrpession test fairly well, but out on the road, with the engine warmed up and you hit some boost - sploosh - coolant all over the engine bay.

With the engine off and coolish, if you squeeze the upper radiator pipe with the bottle cap off does it gurgle coolant around? What about with the lower? (Might help blockage awareness)

Is the cap on that designed for pressure relief? If so it's possible the cap is bad (I know you said you swapped this but I mean... stranger things have happened)

It could also be the thermostat's wiggle valve (or whatever it's called) got stuck or blocked, or... you have a bad thermostat. I don't know that I'd go with headgasket just yet.

But BECAUSE YOU'VE HAD ISSUES, you should DEFINITELY TEST your thermostat with boiling water to be sure it works or doesn't work.

JohnMc said:

Sounds like it could be a very slight HG leak issue, where combustion gasses can force their way into the cooling system only under stress, but coolant isn't able to leak the other way, and oil and water aren't mixing.

Get a bottle of this stuff to verify: http://www.autozone.com/test-scan-a...st-kit/oem-block-tester-test-fluid/391381_0_0

Worthwhile double checking before tearing the engine apart.

I've had Cometic's fail on me twice in a very subtle fashion. They even comrpession test fairly well, but out on the road, with the engine warmed up and you hit some boost - sploosh - coolant all over the engine bay.

Click to expand...

John... do you just paint that onto the block HG area? Or what?

You use it in a tool, it sucks the air from the coolling system through the fluid. The fluid changes color if there are HC's present.

http://www.autozone.com/loan-a-tools/block-tester/oem-block-tester/391378_0_0

They have a free-rental on that tool. They charge you the full retail price, but refund 100% when you bring it back.

I'll definitely be taking all of this into consideration, I'd like to just get all the other possibilities out of the way before having to buy the special tools to change the headgasket and doing so.

Definitely trying the testing tool just to give me a quick and easy verdict

While even i'm assuming its probably a headgasket just from my past luck with whiteblocks haha

Thanks everyone

Did you see the *new* engine run beforehand?

I saw a similar issue on a car I went to check out. Owner claimed that the heater core just "exploded", but the car ran fine.

Got there, bypassed the heater core, and the car indeed run well. Coming back from the test drive, there was steam coming from the pass side of the engine. Popped the hood to see coolant leaking past the cap. Shut things down, and took the cap off. The cap looked new and the gasket was intact. Started the engine with the cap off, and coolant shot 2' into the air. Needless to say, I passed on the car.

There was no water in the oil, but I assumed HG at the very least. Also explains why the heater core "exploded".

Well to be honest no, the engine was a low mileage donor and we got it with it being already out of the other car.

I know we should have seen some thing like this coming but I guess we were a bit too hopeful.

While it is leaking from the cap, with the cap off, it doesn't quite explode out like you mentioned. It sort of just calmly overflows.

I'd do a pressure test on the coolant system.

The wife's '97 855 GLT LPT had a mystery leak (After we found a split expansion tank). It steamed/leaked coolant on her once, and we assumed it to be the bad expansion tank. After that, the coolant level kept dropping, but there were NO visible signs. No puddles, no steaming from under the hood, no white smoke out of the exhaust. Nothing.

I'd made a cap set-up to be able to pressurize the system with one of my bike pumps. Pumped it up to 15psi and almost immediately found the leak from one of the turbo coolant hoses that has a very small leak. The coolant was leaking out onto the exhaust and burning off, before it had a chance to drip.

Now that wouldn't cause pressurization of the system, like you're having, but until I did that, I was expecting a bad HG also.

I'd give that a shot, perhaps removing spark plugs to listen in on the combustion chambers to see if you hear a leak.

Well theres your problem..........



Probably should have assumed but was looking for a bit of hope that it wasnt haha

still no definitive proof that it is a blown HG, could also be a hairline cracked cilinder liner (not uncommon on some of these whiteblock engines)

Janspeed said:

still no definitive proof that it is a blown HG, could also be a hairline cracked cilinder liner (not uncommon on some of these whiteblock engines)

Click to expand...

Well, I guess a failed HG is the best case scenario at this point.

Cracked liners seem to be an '04-'07 V70R thing, not saying it's not possible for it to happen to an older motor but it would be a fluke in my experience. More likely it's a headgasket.

So a bit of an update on our issue, we changed the headgasket and we still have the same issue but we did actually thoroughly look over the block and the head and saw no fractures or damage whatsoever so we're currently at an impasse.

That is disheartening. I had a very similar issue, but a new overflow cap fixed my problem. Sorry for your luck, dude!