Thread: 300 tdi high oil pressure blowing turbo seals

Hi,

It has been a while since I was last on here but all has been going well until just before Christmas. Back story is '97 Disco 300tdi auto 320Ks on the clock. Blew a turbo seal and dumped oil into the intercooler and the exhaust 200kms from home. The car is with the local town mechanic. Turbo sent to Newcastle to a turbo specialist. The turbo was still 'with in spec' according to the turbo specialist so it was deemed a rebuild kit could be put through it (it also received a new core) which the turbo specialist did. Anyway after several more blown turbo seals and subsequent rebuilds the mechanic has discovered that the engine oil pressure was too high. Subsequently, oil pressure relief valve and spring replaced. Alas that didn't solve it as the oil pressure is still too high (not sure what the pressure was recorded at but it seems greater than the upper limit which I recall is 55psi). The thinking is now that there is a blocked oil gallery somewhere. There is no abnormal oil pressure in the crank/sump as the mechanic has driven around with the oil filler cap off and it hasn't been blowing the dipstick out but did blow the turbo seal. At idle everything looks good but under acceleration/load the seal blows.

What else could be causing the high oil pressure? and somehow blowing the seal in the turbo? Is there any hoses/return hoses that could be blocked that would cause the blowing of the seal. I'm thinking from the camshaft return to the sump perhaps but then I think the hose would just blow off or split which hasn't happened.

Appreciate everyone's thoughts. Thankyou in advance.

PS had new radiator installed about 3 years ago but not sure if it was OEM.

Originally Posted by mike123

Hi Dave,
The return from the turbo has been checked and is clear.

Good thought about the oil cooler thermostat - I get the mechanic to check that in the morning - where abouts would it be located. I have the Rave CD. (I suspect that it is page 36 & 37 of the overhaul section of the Rave CD, thermostatic valve being on the oil filter head)

With the pressure relief you mean the oil pressure relief valve in the sump in front of the oil pump? That has been replaced with a new one including spring I'm told by the mechanic.

Just because its clear when its off, doesnt mean that it is when its got the turbo sitting on it and is tweaked into position.

yes its on the oil filter head.

just because the spring and ball has been replaced means very little if the oil dump port is obscured. Usually only happens after bad fitment work, if the wrong spring or if the pump has chewed a bit of sealastic thats gotten past the strainer.