2000 V70 XC ejecting coolant at return tank

Rocket99 · Post by **Rocket99** » 23 Jun 2020, 13:22

Unfortunately a replacement 56 engine B5244T has a cylinder head problem, when its up to running temp it ejects coolant out the top of the return coolant tank.

Repair pal says average head gasket repair about $1600. That is not bad to resurrect such a slick looking Volvo V70 XC. If its real.

One big question before relegating this nice low miles Volvo to the wrecking yard is, is there a way to judge if it has deeper problems.

A coolant pressure test held about 20 psi well. Following that there was an overheating event the first time I "went into town"

radiator fan now seems to run well when it gets hot enough

This engine has good compression, low miles 72K,

Do any of you wizened Volvo guys and girls have ideas, further diagnostics to judge whether to throw in the towel or get someone to pull the head, see now bad things are.

I'll get a refund from the engine seller, partial refund from the bone head installer.

thx in advance.

Post by **misha** » 23 Jun 2020, 17:49

How come that compression is ok along with cooling system if there is a problem with head?!

That is the purpose of the line on top of coolant tank.

Compression checks ok,no oil in coolant...no coolant in oil,proper cooling system pressure,doesn't overheat....i don't think that the engine have head problem.

How did you came up with this conclusion?

Post by **erikv11** » 23 Jun 2020, 18:12

Because there are three different chambers kept isolated by the head gasket, and head gasket leak(s) can be uni- or bi-directional among any 2 or all 3 of them.

I'd do a test for combustion gases in the coolant. If this is a head gasket problem, in this case there must be combustion gases in the coolant.

Are you sure the problem is not just an aging or aftermarket coolant reservoir cap?

Post by **misha** » 23 Jun 2020, 18:16

But...wouldn't there be a higher than normal pressure in cooling system?
Cooling system hoses would be pressurised and hard in that case....or i am missing something here.

Post by **erikv11** » 23 Jun 2020, 18:27

I see - yes misha that makes sense, so that also favors the idea that the cap is bad.

I'd still test for combustion gases because a positive is totally diagnostic for bad head gasket. Negative is not.

Rocket99 · Post by **Rocket99** » 24 Jun 2020, 08:46

Thank you for your comments Misha.
It did eject coolant from return tank, which is an aftermarket (junk quality) item, during the first "10 mile" run . The new cheap junk cap on it popped right off, apparently the tank it became soft from heat and the threads did not hold, it nearly popped clean off.

1- the day before that run I did get good coolant pressure retention after putting a new (after market) coolant return tank cap. I used pressure pump with gauge a). zero coolant system pressure, then added that new cheap aftermarket cap then it immediately retained 20 psi. with very slow loss of pressure. Then extended idle up to full temp it did not blow out coolant, short local road test, no problem with coolant blow out. Then I became confident and tried a run into town. In town got occasional flash of low coolant light. When I lifted the hood that cheap tank with cheap cap had nearly popped clean off the return tank, did not retain pressure.

A few days ago I ordered Volvo OEM return coolant tank and cap, I will have and install those soon. That cheap junk after market return tank had become soft with increasing engine heat and the threads of the cap did not hold.

Thanks again Misha. I now have hope I have not wasted so much money and time with with this engine, and with better quality cooling system components this engine will work out.

Craigslist here always has numerous Volvos with these modular engines with blown head gaskets. That is telling us something. Also the fact dedicated Volvo people who understand these engines like them because they do hold up but you have to be on top them. It seems the cooling system is, let just say under or marginally designed so works but it must be meticulously always well maintained.

My mid 80s Mercedes turbo diesel is solid as a rock put it together right, slam the hood and forget it.

Thanks again Misha

Rocket99 · Post by **Rocket99** » 24 Jun 2020, 08:49

erikv11 wrote: 23 Jun 2020, 18:27 I see - yes misha that makes sense, so that also favors the idea that the cap is bad.

Yes Erik thank you. I will for sure follow your suggestion about CO in coolant.

Please see the response to Mishas excellent comments, you two are saying my bacon potentially.

I'd still test for combustion gases because a positive is totally diagnostic for bad head gasket. Negative is not.

Rocket99 · Post by **Rocket99** » 24 Jun 2020, 08:51

misha wrote: 23 Jun 2020, 18:16 But...wouldn't there be a higher than normal pressure in cooling system?
Cooling system hoses would be pressurised and hard in that case....or i am missing something here.

Yes Misha I will follow up your comments here also.

Thanks again

Post by **scot850** » 24 Jun 2020, 12:20

I regularly warn folks of NOT running these engines (particularly turbos) on regular gas. Particularly when the engines are running under load they will burn lean and take out valves. I put my hand up to running a 93 850 NA on regular around town where it did short runs and did not work hard. However, if I was going on a highway or running hard it got a tank of premium. Since then I have had turbos and they only get Premium gas. I am fortunate I do not do a high mileage so the difference in a tank of fuel is fairly small over a year.

The other reason I use Mid range or Premium, is many regular gas makers do not use any cleaning in their gas. This has been improving up here but even so I will stick to Premium.

Neil.

Post by **misha** » 24 Jun 2020, 12:51

Let's see if new coolant and cap will make things right.

I must have a mad luck....since my tank and cap are still original.
***Knock on wood***