Hi to every one,

I been having to top off my coolant a lot more than normal. Yesterday,
I found the culprits location. The leak seems to come from the behind the exhaust manifold at the back end by plug # 6. No coolant in the oil and car runs fine just having to add more coolant. The car is almost at 200K

Is this an indication of bad head gasket???

I agree with the other gentlemen. Start with the heater hoses. If original one of them is the most likely culprit. The heat back there might have softened it/made it squishy and caused a slow leak. Check them!

Don’t recall hearing anything about the coolant pipe corroding.

On a related note, based on years of reading both the RWD and FWD forums the 5 cylinder engines very rarely have head gasket failures as they are an all-aluminum engine. I suspect this also applies to the 6 cylinder engines as it is essentially the same engine with one more cylinder. It is a modular engine design. Therefore, there is no heat disparity between the metals in the head and the block since both are aluminum. Unlike an aluminum head and iron cast block design. Typically the only way to do in a head gasket or head in these engines is by running out of coolant.
--
Will I buy another Volvo??? We'll see....

Thanks to all for the great ideas.
I'll let you guys know what I find, it might take a while going on a 3 week trip out of the country.

Dear hf63,

Hope you're well. Never having owned/worked-on any six-cylinder Volvo engine, I usually leave to others, related questions.

Based on diagrams in Volvo VADIS - a superseded dealer parts/service database - I wonder if the problem is: (a) a heater hose leak or (b) corrosion in the metal pipe that runs behind the exhaust manifolds, to which a heater hose attaches.

When were the heater hoses last changed? If the in-service hoses are factory-original, they are years past the end of their service life.

It a heater hose ruptures, coolant will be lost in a minute or so, the engine will over-heat, and you're looking at a headgasket replacement. On six-cylinder engines, that involves replacing the chemical gasket or the entire head, if it warps. Neither is a "cheap date".

Thus, you need to ascertain - pronto!!! - the source of the coolant leak. If a hose is leaking, do not drive the car until you've replaced both heater hoses!!!

The heater hoses are #9155499 and #9161000. Each hose costs $30-40 from a US-based Volvo dealer.

If the coolant pipe has corroded and is leaking, that is Volvo Part #9142746. Unfortunately, this pipe no longer is available from Volvo. But you might find a serviceable unit at a salvage yard.

Do not drive the car until you ascertain the source of the leak and replace the heater hoses and/or the coolant pipe.

I presume the heat shields are secured to the exhaust manifolds by hex-head bolts. Saturate them with PB Blaster or a similar penetrating oil daily, for several days. That allows time for the oil to percolate through micro-channels in the corrosion and so the weaken corrosion bonds.

Before trying to remove the bolts, move the wrench a few thousandths of an inch, as if you were tightening the bolts. This can help to break the corrosion bond. Then, very gently and slowly, try to remove the bolts. With some luck, they'll come out.

Hope this helps.

Yours faithfully,

Spook

Any chance it's a heater core hose going into the firewall?
--
Post Back. That's whats makes this forum work.

I am going to install a bypass hose at this location to eliminate the heater core.

How do you remove the exhaust shield???

I meant hoses not the core.
--
Post Back. That's whats makes this forum work.

Just bumping you up to the top again so you might get a response this weekend...
--
Will I buy another Volvo??? We'll see....