Hi gang, I have a '96 D1 V8 GEMS here in California, with a rare R380 five speed. I bought it two years ago from the original owner in lovely cosmetic condition and I've been chipping away at all the little problems while driving it. The PO had the engine rebuilt by a machine shop. The owner assembled all the external parts and did an OK job, I've been chipping away at tidying up some of the things that weren't quite up to par.
The truck has always had a delay prior to building oil pressure from a cold start. Recently that got worse, then the oil light came on while coming to a stop, and I could hear lifter clatter so I shut it off immediately. After letting it cool for a while, I restarted and got oil pressure back. I was careful to keep the idle up at stops on this last trip and now I have parked her up for some investigation.
I have the sump and front cover off for inspection. The oil pump looked fine but the front cover is somewhat scored. I am not sure if that is the cause of low oil pressure or not. I will take the cover to a machine shop while it's off and see if they can face the pump area hopefully after building it up a bit. If not I will have to get a new one from the UK at a high cost. I have new oil pump gears and all the gaskets and ancillary bits on hand. While she is apart I have looked through the sump and everything looks good, although I doubt I could see if there was a spun cam bearing etc. I would like to take off a rod cap and see how the rod bearing looks, however I am not sure if the bolts are reusable or not. The factory manual is pretty vague!
I am pretty confident that the lower end is in good order since it has under 40K miles, was built by a reputable shop and the inside is squeaky clean. There was no debris in the sump and there has never been any oil usage. I hope tidying up the oil pump will get me going again. It wasn't replaced during the rebuild because they are not commonly available like the later D1 and D2 front cover.
There is nothing in the manual about the sump gaskets. I've also removed the flywheel inspection plate as there was a wet oil leak in that area. I assumed it was the rear main, but it is bone dry inside the bell housing and on the back of the flywheel. The sump was installed with a cork gasket, and the inspection plate has a rubber strip across the top and was gooped on with RTV. That doesn't look right to me. I would like to replace the rubber strip but can't find a part number or any reference to it anywhere. I'm also not sure whether to use a cork gasket, I've read that the GEMS engine is designed to be run with sealant only. I am pretty sure the leak was coming from the rear main bearing cap as there did not appear to be any sealant under the cork gasket to stop oil traveling along the cap to crankcase joint.
I would love to hear from anyone who has done this job, specifically with regard to what I mentioned:
The truck has always had a delay prior to building oil pressure from a cold start. Recently that got worse, then the oil light came on while coming to a stop, and I could hear lifter clatter so I shut it off immediately. After letting it cool for a while, I restarted and got oil pressure back. I was careful to keep the idle up at stops on this last trip and now I have parked her up for some investigation.
I have the sump and front cover off for inspection. The oil pump looked fine but the front cover is somewhat scored. I am not sure if that is the cause of low oil pressure or not. I will take the cover to a machine shop while it's off and see if they can face the pump area hopefully after building it up a bit. If not I will have to get a new one from the UK at a high cost. I have new oil pump gears and all the gaskets and ancillary bits on hand. While she is apart I have looked through the sump and everything looks good, although I doubt I could see if there was a spun cam bearing etc. I would like to take off a rod cap and see how the rod bearing looks, however I am not sure if the bolts are reusable or not. The factory manual is pretty vague!
I am pretty confident that the lower end is in good order since it has under 40K miles, was built by a reputable shop and the inside is squeaky clean. There was no debris in the sump and there has never been any oil usage. I hope tidying up the oil pump will get me going again. It wasn't replaced during the rebuild because they are not commonly available like the later D1 and D2 front cover.
There is nothing in the manual about the sump gaskets. I've also removed the flywheel inspection plate as there was a wet oil leak in that area. I assumed it was the rear main, but it is bone dry inside the bell housing and on the back of the flywheel. The sump was installed with a cork gasket, and the inspection plate has a rubber strip across the top and was gooped on with RTV. That doesn't look right to me. I would like to replace the rubber strip but can't find a part number or any reference to it anywhere. I'm also not sure whether to use a cork gasket, I've read that the GEMS engine is designed to be run with sealant only. I am pretty sure the leak was coming from the rear main bearing cap as there did not appear to be any sealant under the cork gasket to stop oil traveling along the cap to crankcase joint.
I would love to hear from anyone who has done this job, specifically with regard to what I mentioned:
- Any info about similar oil pressure problems
- Should the sump be installed with the cork gasket or sealant
- What is the part number for the flywheel inspection plate gasket strip
- How best to seal the sump and inspection plate