Ok, so I just finished my engine swap in a 1998 Buick LeSabre. Donor ended up being a 2004+ Impala. Best I could tell was that the Plenum was stamped Feb 02, 2004. So, the install went great with some suggestions from this forum and others....a big thanks to those who assisted!

Now the question:

Once my LeSabre warms up, I'll notice a drop in oil pressure when I slow down or come to a stop (ie - getting off the interstate or at a stop light). I'll stick right at 40psi when I'm running, but then drop down to the red when I'm stopped. Just a few things I've observed

1) Only happens when the engine is warm
2) Previous engine called for 10W-30 but donor calls for 5W-30. Only had 10W-30 on hand for the oil change
3) 1qt of the oil change is Marvel Mystery Oil. Supposed to help clean the engine, but the consistency is more like Water
4) Reused the Oil Pressure Switch. Was working fine before. Only a couple months old, so I pulled it before I yanked the engine, then reinstalled after the new engine was set.


Any thoughts???

I think you need to wait until you do the next oil change when you get that Marvel Mystery Oil out of there to get accurate results. I assume you are only leaving it in there for 50 to 100 miles???

Perhaps a rookie mistake, but I wasn't aware that you were supposed to use the MMO as a flush. Had heard that you could use it as a cleaning additive. If you have experience with using this or other information, I'm all ears.

My reasoning for using as a cleaner was that the plenum that came off the donor engine was built up with carbon and the peek that I got at the pistons looked to have carbon on them as well. Perhaps it'* from sitting (at least 2 years), but I wanted to get everything cleaned up inside.

I am not familiar with the product you used, but I would not leave a cleaning solution in the oil long term. It thins the oil out, and picks up all the crap. If you don't change it, the crap just stays in the oil and gets re-deposited. Defeats the purpose of the cleaner. I use Seafoam and leave it in for 50 to 100 miles.

I have had the same problem in my 98 SSEi. I thought I had major engine problems. I changed the oil and replaced the Fram filter with a Purolator and the problem went away. I used to change my oil and filter, then go 3-4000 miles then just drain the oil and replace it without replacing the filter, then change the oil and filter after 3-4000 miles again. It was fast and easy. I thought I was saving time and money. The filter that caused my oil pressure to drop into the red zone had been in the car for about 7000 miles. I don't use Fram filters any more and I don't do oil changes without replacing the filter. This was 2 or 3 years ago and I have not had a problem since.

Fram oil filters are crap.

I agree with the sentiment on Fram. I won't use them. Has anyone had experience with the O'Reilly house brand MicroGuard? Guys behind the counter swear they are just a notch down from Wix, but who doesn't want to move their merchandise?

Here'* a follow up: Oil Filter for an 89 Chevy Celebrity 2.4 fits perfectly on both my 96 Bonne and my 98 LeSabre. Only diff I can see is that the filter is like 2-3 inches longer. Is there any benefit to using the longer filter? It would seem that more surface material = more cleaning capacity.

some oil filter comparisons
did you see the hole ...WTF




I use AC Delco . i like the idea about putting a magent on the oil filter to attract metal particles. For cleaning the top end I use SEAFOM. I put half the can as per directions in the fuel tank, then wearing safety glasses I pour the rest of the can in, slowly, in through the vacuum hose to the manifold while the engine is running. I unplug the hose and plug my own hose in with a funnel on the end. I pour in slowly till the engine dies, then let sit for awhile, then redo till the can is gone. when the engine dies there is a very high chance of the engine spitting some back at you so wear eye protection.

Seafoam rules. I put 1/2 a can into the oil 50 miles or so before every other oil change, and put the other 1/2 into the gas tank. Also good for a top end clean by pulling it into the intake (I use the brake booster hose), and I used it once in the transmission just before a pan drop.

I do believe there is more cleaning capacity with the longer filters, I went with a standard size filter on my last change, but plan to use the longer filters from now on, I have a pic of part numbers that work as replacements for the smaller filter on the 3.8L V6