The V8 Owners Forum -

Hi,

Just got my mega-squirted 3.9 up and running in the last 24 hours

Trying to sort a few snags and I suspect I have an air leak in the manifold area. Are there gaskets available for the plenum base and plenum top?

I fitted them using permatex sealant but i'm wondering if this has worked or not.

None of the manifolds I stripped for parts had any gaskets but that doesn't mean much!

Cheers

Ben

nah mate its a sealer job,
i use either silicone or hylomar when i do mine,

Cheers,

Will have to do a little more investigation. I'm sure that I could hear an air leak

Don't you have to be careful with Silicon sealers? I thought that they killed lambda sensors or something (not sure on this).

I'd be interested to know either way as i will be going MegaSquirt soon and dont want to kill mine by using the wrong sealer.

Took me a while too find mine look under the plenum where the heater pipe should be, there's 4 holes there that need to be plugged

Wahhhhh! Hope not, will have a look later!

Think i've found the leak. Unfortunately it seems to be around the bottom of the injector on number 4 cylinder. I suspect the O-ring might have got buggered when I installed the injectors. I used the recommended silicon grease but they were bloody tight on that bank whereas the other slipped in a treat.

Haven't stripped it to check yet but has anyone else had this problem.

Where is the best place to get replacement o-rings? They seem rather expensive from rimmer bros. Surely they must be pence each?

When I was an apprentice I saw a diagnostic trick for the Bosch setups if a leak was suspected.
A syringe was used to dribble brake fluid around the injector base one at a time with the engine running and if the exhaust gas suddenly went white then it proved a leak at that point saving a lot of head scratching. A quick squirt of water washed the brake fluid off after the job.
Alternatively, if you can hear the leak then a few drops of engine oil around the injector will seal it up and the noise would stop, identifying the suspect seal.

Already identified the leaking injector using a piece of tube as a listening device but I think I might try your method as a double check before stripping it.

Any idea as to where to get O-rings? I presume the material isn't anything special.

I could probably find them quite easily, but I am in Thailand right now, so not much help to you, sorry.

Bent,

Try Landrover agents, anything from Rimmers is an arm and a leg, was speaking to a guy who bought a standard 3.9 cam from Rimmers, their price £185.00. V8 Tuner £85.00.

Kevin.

Thanks mate will do,

Confirmed the leaking injector today with the engine oil trick, sucks it up as fast as you can pour it in so it must be quite bad!

Does the plenum base have to be removed to get the injectors out or can they be wiggled free with it still there?