General: 70: 2.5 10v engine noise

[BIGH66]

when i start my 2.5 10v for the first time in the morning its started making a chuffing/exhaust spit type of noise(engine area) for a couple of seconds then stops and wont do it again until the next time its left all night?all ideas welcome cheers mark..

[MikeG]

Possible exhaust blow at the manifold or downpipe which as it heats up expands and seals .Worth a look

[BIGH66]

Originally Posted by MikeG

Possible exhaust blow at the manifold or downpipe which as it heats up expands and seals .Worth a look

Cheers mike i,ll get it looked at

[Clan]

The exhaust manifold branches are prone to splitting on these 10 valve engines , even when volvo changed the tubular stainless steel ones for conventional cast iron it still happened ... Your symptom and noise is typical of a split exhaust manifold ...

[scotsgent]

Taking the heat shield off the top of the manifold at the top back of the engine is a 5 minute job, you will then be able to see the manifold and its branches. Spray some soapy water over the entire manifold and start it up, you should see bubbles where the crack is, but if it is a crack it will seal itself quickly because of the intense heat in the manifold, so you should be well prepared with the soapy water and torch before you start up. Best get in position, spray and get the wife to start the car. The crack I had was very apparent. When cold I could see it, but it was invisible when hot.

I had a problem getting a second-hand manifold for my 10v. On some models of the V70, the flexible section of the downpipe is integral to the manifold, on others it is integral to the downpipe - make sure you get the right one.

I ran with the crack in the drivers side branch (extreme left as you look down on it), for more than a year. Apart from the tractor-like sound on start-up, it never got any worse nor did it seem to affect performance since the crack would self-seal within a minute with heat as the engine warmed. The crack I had entirely encircled the branch.

It COULD also be loose manifold nuts but you can easily check and tighten these if needed with the heat shield off.

I eventually found a used manifold of the correct type and got my local garage to fit it, the entire cost was around £70.

Cheers, Terry

[Clan]

its not a bad job to get off , you could get the crack welded , it may last a long time or could crack again but a lot cheaper than a new manifold . The nuts are only prone to loosening on the turbo T5 and T4 engines after a while and by no means on all of them ...