very low oil pressure

[suprahero]

I just got my wifes car back from the shop last week. We had a remanufactured motor installed. She drove it down the road today to listen to the new exhaust I had installed today. When she got back she said that the oil pressure was low and that it never got above 20 psi while she was driving. I was hoping that it is a faulty sending unit or gauge. My turbo gauge I know is bad, because it never goes past 1psi, but I put an aftermarket gauge to it and it boosts to 6psi. Hopefully the gauges are bad, but I can't risk it. How hard is it to put a oil pressure gauge to the block. I know where it's got to install, but can't remember what all I've got to remove to get to it. Does anyone have any suggestions?
The manual saids that it may be a faulty relief valve, but I don't know where that is either. Would the new motor come with a new oil pump? It doesn't make sense to put an old oil pump in a new motor. Thanks for your help.

 

[aye mate]

What type and weight of oil is in there? Depending on the type of oil, ambient temperature and how your wife drives the oil pressure may not go over 20psi.

 

[suprahero]

It has break in oil. I don't know what weight it is, but the guy said to use it for 500 miles and then change it to 20W50, but I'm going to use mobil 1 synthetic instead. She also said that she floored it and it didn't get over 20 psi. She didn't drive it but about three miles though, luckily. Thanks for responding so soon. Any suggestions anyone?

 

[Yellow 13]

did you check the dipstick to make sure it was full. since its a remanufactured motor it may drink a quart just filling up the lines and oil filter.

 

[xarewhyayen]

my guess is low oil... if ipressure kinda goes down a lil bit as u rev more, its prob low oil. check the dipstick and add if nessecary. new/rebuilt motors tend to have alot of blowby since the piston rings arent seated so you may have burnt a decent amount of oil already.

 

[suprahero]

Yes I checked it earlier that day before she got home and drove it. I was checking all of the intercooler pipes to make sure they were tight. I drove it earlier in the day and it had normal oil pressure. As I got closer to home I noticed that it had dropped to right below 20, but I wasn't going but about 40 mph. I didn't think that much about it at the time. Now it's got me worried, because when it was idling this evening, it was almost on 0. I cut it off and haven't cranked it since.

 

[suprahero]

I did notice a lot of oil in the upper ic. pipe today. I cleaned it out, but their was more oil in there than I wanted to see. I'll go out and check it again right now and see if it's low or not.

 

[Yellow 13]

Bad turbo seal? clean out the ic pipe, put in some fresh oil and go for a short drive.

 

[aye mate]

My vote is still on low weight oil. Change it to Mobil 1 15w50 and put in 6 quarts. That will give you some good OP.

 

[suprahero]

I just went out and checked the oil and it was fine. I then cranked the car and it was idling with 20 psi. When I revved it just a little it went to 40 psi. What gives? Earlier it had almost no oil pressure now it's perfect. Could it be the gauge? Should I still have the pressure checked? I'll just keep an eye on it for now. I'm open to any suggestions. Thanks.

 

[suprahero]

Aye Mate, are you serious about the six quarts? My car only takes five quarts and it is right at full. Isn't it bad to put in too much oil? Were you just kidding?

 

[aye mate]

Make sure that the sendeing unit is clean and the wire is secure.

 

[Yellow 13]

check the oil pressure sender unit. its in the block on the front of the exhaust side. looks kinda like a bell.

 

[suprahero]

Thanks for the help. I'll check the sending unit tomorrow morning and make sure the connections are good and clean. Thanks again.

 

[aye mate]

Aye Mate, are you serious about the six quarts? My car only takes five quarts and it is right at full. Isn't it bad to put in too much oil? Were you just kidding?

Yes, I put in 6 quarts every oil change. Somewhere in IJ's rebuild thread he measure that a stock oil pan will hold up to 10 quarts without the oil touching the crank. And yes it is bad to have too much oil in an engine, I believe because the crank will stir up the oil and cause air bubbles which get in between the bearing and the oil and they don't lubricated well enought. But 6 quarts in a 7M will not hurt anything.

 

[Yellow 13]

10 qts in a stock oil pan...You sure? I could understand that being true for his group A oil pan.