Forumites,
A little while ago I wrote about a small oil leak I had the at the front of the sump on my 3.0 ltr TD. I thought I had the problem solved but after a run out the oil leak was back.
I now had a series of options, drop the vehicle off at Nissan for three days to fix it and pay around $1200 bucks for the pleasure, live with it, try and fix it with Sikaflex or some other sort of goop, remove the gearbox to get at the two secret bolts between the engine and gearbox or I wade in and fix it myself. I went for the latter, armed with $90 worth of spares and a DVD manual I bought off Ebay for $8 (Thanks for pointing me in the direction Hugh, fan bloody tastic, would recommend to anyone).
The front of the engine has now been removed and I've found the leak, yes it was the joint between the sump and the front cover, one small quadrant on the right hand side of the sump gasket face between the bolt hole and the front plate. This could of been caused by over tightening of the plug which could of deformed the sealing face (maybe).
I'm glad I've found the leak and now I've got the right sealant to put everything back together, (unfortunately) I had to go to a Toyota place to get it. The Toyota RTV OEM sealant talking to a wide range of people from all different backgrounds seems to be the go. That will do me before we get into a big hoo har about which is best, so I'm done with tyres, batteries and now silicon sealants.
Just for your info I got a really good response about sealants and the best ones for different applications from a technical dood at Hylomar in the UK, really good response with good unbiased opinions.
So this is the last post on my oil leak, the reason I put this in is there are two people I work with who have repeatedly been back to Nissan being told different reasons as to why the vehicle has this oil leak from being the plug leaking which has no oil behind it and no pressure, hard to see why it leaks really..... To problems with the o-rings. The only o-rings that I can see that would cause a problem would be the o-rings behind the power steering pump and the vacuum pump. The o-ring behind my vacuum pump was OK but the actual casing o-ring between the two halves of the vacuum pump was damaged, this has now been replaced, could
well of contributed to the leak. It's a good idea to check these first seeing they are a one hour job to replace (plus a bit of power steering oil obviously).
These vehicles are coming close to coming out of warranty so Nissan might be just waiting until the warranty expires until the real problem is identified. I advise anyone that has evidence of this leak to persevere with Nissan agent to get the leak fixed before the warranty expires, keep all documentation to prove the amount of times you've tried to get the leak fixed. Persevere it's worth it, I didn't I've learnt the hard way.
I now have the evidence that the Nissan coolant additive in the best I've ever used, the cooling system was like new, no erosion or corrosion at all. My Nissan is a 2000 model 153k on the clock, the engine coolant ways and the radiator were in mint condition, no discolouration, no crud, nothing, perfect, I was stunned as to how good it was. This is just info / feedback.
Hope this info is of use to someone, as usual these are my opinions other peoples may vary.