RWD - Coolant leak location - URGENT !!!!

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Coolant leak location - URGENT !!!! 900 1997

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Based on diagrams in Volvo VADIS - a superseded dealer parts/service database - I wonder if the problem is: (a) a heater hose leak or (b) corrosion in the metal pipe that runs behind the exhaust manifolds,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



New Having to add coolant/ leak location [900][1997]
posted by  hf63  on Thu Apr 18 09:17 CST 2019 >

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