Hello all,

I own a 97 850 glt wagon with 162k on the odometer (~165k). After reading a lot about the pcv problems our cars have i thought i narrowed down the problem but i have added symptoms.

I started getting oil on top of the head and around the plugs but my main pressure is in my coolant system. My overflow bubbles at idle and cant be driven without burping out all my coolant. If i unscrew the overflow cap and relive the pressure i loose my coolant. If i tighten the cap the lower coolant hose that attaches to the radiator will blow the clamp - that was fun!

I dont notice any milky oil or white smoke so i dont think it is the head gasket but all the problems i have read on this site about the PCV valve puts pressure in the head and oiling system and not the cooling system. HELP!

 

Andy, you could have more than 1 problem...

If oil and coolant is NOT mixing, you likely DO NOT have a head gasket problem YET!!! What is the temp doing? Does it get hot on the guage? You are NOT SUPPOSE TO BE MESSING WITH THE COOLANT RESEVIOR CAP with the car hot/warmed up. Leave the cap alone. Only take the cap off of the res if the level is low with the car cold.

You likely have a clogged PCV system. You can drive the car warm, stop the car, leave it running, pull the dip stick out a little and see if you see smoke.

 

Quote:

Originally Posted by rspi

Andy, you could have more than 1 problem...

If oil and coolant is NOT mixing, you likely DO NOT have a head gasket problem YET!!! What is the temp doing? Does it get hot on the guage? You are NOT SUPPOSE TO BE MESSING WITH THE COOLANT RESEVIOR CAP with the car hot/warmed up. Leave the cap alone. Only take the cap off of the res if the level is low with the car cold.

Yes I do have smoke! I am going to go ahead and do the PCV system upgrade. When you said I could have multiple problems... what else could be causing the bubbling in the coolant overflow?

I was down 4 quarts by the time I took it into the shop, which i never let it get low, and I have oil everywhere. Do you think that the coolant was boiling because I had no oil to help with the cooling? Thanks for your help! I feel so much better just know what is ahead of me.

 

Lots of things could cause the coolant issues. Water pump could be bad (check the weep hole by removing the timing cover and doing a visual inspection.

You have to remember, the coolant you are losing is going SOMEWHERE. It's going one of 3 places:

1) on the ground - leaking hose, cracked block, water pump going bad, etc.

2) into the crankcase - blown head gasket

3) out the tail pipe - see problem #2

I'm sure there could be other causes than JUST the ones I listed, but those are going to be the most likely causes for each individual symptom. I hope it's nothing major.

 

I don't know what could cause bubbling up in the coolant reservoir, except a blown head gasket.

Not sure if this would cause bubbling, but possibly if the water pump impeller broke off...

Do a compression test; that should be informative...

Did you say your engine was 4 qts low on oil?? Dude, these things only hold 5 or 6 qts!!

Have a feeling you have serious engine problems; sorry.

 

You can blow a head gasket between the cylinder and the water jacket and not mix with oil. Every compression stroke will pump compressed heat and air into the cooling system and building pressure in your reservoir.

Dont let it sit...I waited a week before pulling the head of my car (which by the way had the exact same issue) and lost my block due to rust.

 

Were you using 50/50 coolant mix when it rusted like that? We had experienced "some" coolant loss for weeks before I got around to it and had no rust. It was my understanding that coolant (in an adequate concentration) would keep that from happening. I would have probably tried some penetrant sprayed/soaked in the rusty cylinders and some manual rotation of the crank before giving it up on that block, as it doesn't look that fargone.

 

You could also have something as simple as a pin hole in the cooling hoses. This would cause bubbles to get into the system because it is sucking air and not pressurizing? That would be the easiest problem to solve. But like ibified said the coolant is going somewhere if you are loosing that much?

 

Hi, Im VERY new to this and all the tech terms. What does PCV stand for? My 1996 850 is also driving me nuts after 553 000km and in South Africa , if you drive a Volvo, Quotes START like you are Bill Gates !

 

The term "PCV" has been around probably since 1960 and stands for Postive Crankcase Ventilation. It means operating the crankcase under vacuum, using restricted engine vacuum, and burning crankcase vapors (stuff that blows by the pistons) through the engine. Volvos are very strange in this regard.

The crankcase vapor handling system on a volvo is not like anything else I've ever seen. That is the system people mean when they say "PCV" on this forum.