Synthetic motor oil

DOODLE50

MEMBER
1989 CHEVROLET SUBURBAN
V8
4WD
MANUAL
200 MILES

I have a RamJet 350 Crate Engine PFI with Iron Vortec Heads in a 1989 3/4 ton Suburban. I bought it second hand with low miles and stuck it in. My question is regarding oil pressure and synthetic oil. This motor has always had Mobil-1 synthetic. The pressure is high at initial start up but after the motor warms up the pressure seems low to me but I have no experience with synthetic oil. Should I be running a high volume oil-pump?

Friday, December 17th, 2010 AT 12:56 AM

3 Replies

DAVE'S BIG BACKYARD!

MECHANIC
262 POSTS

First make sure its the right weight oil. Then you might want to check the oil sending unit, after that it gets pricey.

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Friday, December 17th, 2010 AT 1:29 AM

HMAC300

MECHANIC
48,601 POSTS

No all oil presssure in these motors drop after the oil heats up no matter if it's synthetic or mineral oil. If you runabout 40-50 psi at about 2000 that's ok, if it drops to 20psi or around there that's about normal. Anytime you suspect an oil pressure problem always use a mechanical gauge.

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Friday, December 17th, 2010 AT 1:56 AM

DAVE'S BIG BACKYARD!

MECHANIC
262 POSTS

Yes oil doe's bake thin in all engines. That is as long as the pressure dont get to low, yes a gauge is best. Auto parts stores have the specks&or a book on the engine.

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Friday, December 17th, 2010 AT 2:22 AM