Help with engine noise

[Gareth2510]

Hello to all. I have a 95 940 2.3t manual. It's got a strange noises coming from the engine. Sounds like a gasket or gaskets have gone. Also sounds like air leaking when the engine is switched off. Any help would be appreciated link to the video.
https://youtu.be/tu00fBBijwE

[Moomoo]

Is the performance affected? Is anything loose, plugs, injectors, manifold. It sounds like just one cylinder chuffing! Any fluid loss? Breathing?

[Gareth2510]

Can't be sure on the loss of fluid. I only just swapped out the thermostat and coolant. This car is new to me and arrived this way. All injectors are in and seem ok. Plugs and wires are good distributor cap & arm are new. I can feel air pulsing In between the 3rd and 4th cylinder near the manifold. I guess a compression test is in order

[Clan]

Originally Posted by Gareth2510

Hello to all. I have a 95 940 2.3t manual. It's got a strange noises coming from the engine. Sounds like a gasket or gaskets have gone. Also sounds like air leaking when the engine is switched off. Any help would be appreciated link to the video.
https://youtu.be/tu00fBBijwE

One of the exhaust port gaskets blown just replace the 4 and also the manifold studs and nuts with VOLVO ones ... make sure the manifold face is flat .

[Moomoo]

Originally Posted by Gareth2510

Can't be sure on the loss of fluid. I only just swapped out the thermostat and coolant. This car is new to me and arrived this way. All injectors are in and seem ok. Plugs and wires are good distributor cap & arm are new. I can feel air pulsing In between the 3rd and 4th cylinder near the manifold. I guess a compression test is in order

Head gasket, God forbid? Or exhaust manifold? Any smell of combustion gasses?
You say the plugs are new but are they nipped up?

Typing at same time as Clan! He’s the man , ignore me!👍👍👍😄

[Gareth2510]

Originally Posted by Clan

One of the exhaust port gaskets blown just replace the 4 and also the manifold studs and nuts with VOLVO ones ... make sure the manifold face is flat .

I was thinking if I could just remove the studs and slide new gaskets in. Or is it turbo and manifold off job

[Gareth2510]

Originally Posted by Moomoo

Head gasket, God forbid? Or exhaust manifold? Any smell of combustion gasses?
You say the plugs are new but are they nipped up?

Typing at same time as Clan! He’s the man , ignore me!👍👍👍😄

All torqued up nice and tight. Il try the manifold gaskets and do a compression test.

[AllHailKingVolvo]

The whole thing sounds off-it sounds like there is an aggressive exhaust leak on one cylinder when running. Your manifold has been off at some point in the recentish past as the studs and nuts aren’t original.

Leftfield suggestion, but I reckon you have a blocked cat. If that is the case, the backpressure is enormous and is causing gases to escape from your manifold gaskets and the hissing after the car is turned off is the pressure venting through the downpipe flange gasket.

[Gareth2510]

[QUOTE=AllHailKingVolvo;2832330] yeah that leaking sound when engine switched off is what got me. The cat looks rough as does the rest of the system so will be replaced in due course. But I may remove it and see what it does before I rip the head off and go all out on it.

[Gareth2510]

Originally Posted by AllHailKingVolvo

The whole thing sounds off-it sounds like there is an aggressive exhaust leak on one cylinder when running. Your manifold has been off at some point in the recentish past as the studs and nuts aren’t original.

Leftfield suggestion, but I reckon you have a blocked cat. If that is the case, the backpressure is enormous and is causing gases to escape from your manifold gaskets and the hissing after the car is turned off is the pressure venting through the downpipe flange gasket.

Cat has now been removed. There was a rattle noise but that seems to have been the outer casing deteriorating as nothing inside broken etc. It's still making the hissing sound with the engine running and when switched off. I'm going to take the head off now and see what's what as I'm now seeing coolant dripping under the car. Looking like the HG has gone