Oil and exhaust leaks

[digga951]

Hi Everyone,

Haven't posted on here for a long while...

I currently have the 350i on axle stands at the moment due to a blowing exhaust and figured I would investigate the oil leak thats been keeping the chassis rust free for the last 14 years since I've owned it...

I've attached a couple of pics below. Basically, in more recent years, the car has always smelt of oil when the engine is put under pressure for any amount of time. A 10 minute 70 or 80mph run will result in a hot oil smell in the cabin.

So far, I've not been able to trace the source due to lack of time. Looking at the underside of the car, the most forward point that is covered in oil is the oil pump. I'm not sure if this is standard TVR or not, but the relief vale seems to have a thread coming out of it and that seems to be dripping with oil. I should point out that my car is an ex factory/press car, so may not be standard. The sump and gearbox is also covered in oil, literally driping with it. Does anyone have any guesses as to the source of the leak? What is the threaded rod coming out of the oil pump relief valve nut for? Maybe some kind of adjustable tensioner?

I figured I would drop the sump and replace the gasket with a new one whilst I'm messing around. I can see the original one is cork and is probably past its best. Any suggestions as to what to replace with with? Rimmer Bros have a cork replacement at around £5, where as Ebay turns up some rubber ones at around £20.

The exhaust on my car has always been a pain. The join between the mainfolds and centre box has always been a weak spot, especially due to the 205/50 15 tyres and TVR lowered springs. Not even 3" clearence between the centre box and the ground, which means every speed ramp seems to break the join. Being some £1200 short of a complete new system, I'm gonna have a go at using flexi pipes between the now very rusty mainfolds and centre box.

The over axle part of my exhaust is still reasonably solid, but the final section that the tail pipes are located in has seen better days. Has anyone got a spare piece? My car has the exhaust exit on the far right of the rear bumper.

My car has now got around 170,000 miles on it and is going to drive from Suffolk to Morocco in September, so just trying to iron out a few faults before the trip!

Any opinions, advice or help on the above would be most welsome.

Thanks,

Dan.

[Number 7]

Dan, if the oil pump mod looks like this, it will be a device to adjust the tension on the spring, and therefore the oil pressure. This shouldn't be cranked up too high though, as this will cause wear on the cam / distributor gears.


As for leaks, common places are from the rear of the valley gasket from the rubber seal which is secured with a clamp, or the rocker cover gaskets, and the gearbox selector shaft. Without cleaning everything up first, it could be difficult to find though. As for sealing the exhaust, a friend who races TVR's told me that you can now get a silicon sealant capable of dealing with these very high temps, e.g. head / manifold joints etc. and it remains flexible, unlike the normal assembly paste which sets hard.

[digga951]

Thanks for that! It does seem that I have something very similar to the mod on the relief valve, although I've never adjusted it. Always thought the oil pressure on my car was a bit on the low side (2 bar max when hot and under load), so may be something to fiddle with slightly.

I think I will just replace or rebuild anything that seems to be leaking! Whilst the exhaust and sump are off, it seems silly not to swap out the 2 rubber oil pump-to-filter hoses which also seem to be very oily, along with resealing the relief valve housing.

I also discovered that the fuel hoses I replaced last year have now all split again where they form curves. Goes to show that not all high pressure fuel hose is the same quality I guess...

Does anyone have a spare tail pipe section of exhaust the same as mine that they would like to part with?

Thanks,

Dan.