Volvo 850 exhaust smell in the passenger compartment

nedqlkow

Hello,

First of all, the basic information. Тhe car is a Volvo 850 (LS) 2.5 10V (140 hp.) non turbo with automatic transmission and installed LPG system.

For some time we have been struggling with a very annoying problem which, if not resolved, will result in the car becoming unusable even though it is still in drivable condition.

Therefore, I hope that your vast experience will help me in successfully solving this problem.

Some time ago, maybe over 6 months ago, an odor began to occur in the passenger compartment regardless of whether the air conditioner was running, whether the flaps were open or closed, whether the windows were down or up. At first it was noticeable but not that strong, but over time it progressed and now I would describe it as unbearable and making driving hell.

I would describe the smell as somewhere between an exhaust smell and a smell of burnt oil.

To fix the problem, we started with several steps as follows:

1. New fuel pump and hose inspection.

2. New exhaust manifold

3. PCV revision.

We did the test with the glove - https://www.veed.io/view/2bd752c6-ab...ue&panel=share

However, we decided to replace the flame trap just in case.

We plan to replace the oil trap as well as the attached hoses.

However, the problem remains. Could anyone give me any pointers on where to continue looking?

ramrod

Look over the entire exhaust system

determine whether the odour is exhaust or from leaking oil onto the exhaust

do replace the breather box assembly as fumes can escape from openings if the oil trap is blocked

nedqlkow

ramrod
Look over the entire exhaust system
determine whether the odour is exhaust or from leaking oil onto the exhaust
do replace the breather box assembly as fumes can escape from openings if the oil trap is blocked

Already when the problem appeared, we checked the entire exhaust system, we even blocked the muffler and applied gas to check if smoke would return from somewhere. No such thing is observed.

The next thing we will do is replace the oil separator(breather box) and possibly the rear camshaft seal, as far as I can tell on the 850 it is also a common problem.

1971_144GL

I've had some extremely smelly coolant leaks from the heater core into the passenger foot well. Some of the old coolant has a smell like exhaust when the leak is minor. The heater cores in this car are above the passenger foot well and leak behind the carpet down into the footwell insulation. The first time this happened I spent months looking for an exhaust system leak.

nedqlkow

1971_144GL
I've had some extremely smelly coolant leaks from the heater core into the passenger foot well. Some of the old coolant has a smell like exhaust when the leak is minor. The heater cores in this car are above the passenger foot well and leak behind the carpet down into the footwell insulation. The first time this happened I spent months looking for an exhaust system leak.

If there was a leak from the cooling system, wouldn't it contain antifreeze, hence its characteristic sweet smell?

Otherwise, there is no accumulation of any liquid in the legs of the passenger.