Is it safe to run 20W50 in my LX

[stevesLX]

I have a 89 LX 302 bored 30 over, motorsport heads, flat top forged pistons, 303 cam 24LB injectors,65CFM MAF, edelbrock plenum and intake high volume oil pump, low tension rings and a few other goodies. Anyways it seems as if I am using oil way to quick. I mean like a quart of 10W30 every week. She does burn oil a little but I dont think it nshould be using it that quick. I didn't build the motor but the guy that sold it to me said it will use more oil than normal because of the low tension rings. He was using 20W50. I drained it as soon as I bought it from him because I thought 10w30 would be easier on the motor. He says he thought it was using the 10W30 quicker than the 20W50. Either way I need some advise from you guys the experts on which oil to use. I know a quart a week of Castrol is getting expensive.

 

[HISSIN50]

5.0's come stock with low tension rings [of sorts]. They are the opposite of what I'd use during a rebuild.

I might do a wet and dry compression test to see what's going on.

I have to say that unless you're in a warm location, I'd not recommend 20W-50 for the winter.

You noted the price of oil - if you use synthetic, you might have better luck with dino 10W-30 or 10W-40.

Random thoughts. Good luck Steve.

 

[Mustang_Punk]

check the plugs, do a compression test and look underneath for any leaks from the oil pan, valve covers or rear main, my rear main leaks and it gets rid of oil pretty quick, and 20 dosen't help me at all

 

[DMAN302]

20w50 and colder temps....syrup.

 

[GTA_V6_Mustang]

I am with mustang punk, check for leaks because that does not seem right to me either unless its leaking from the valve covers near the firewall, which would explain you not seeing it. Or a seal.

 

[marine_2003]

I use Valvoline VR and VR1. I run the 20W-50 all year long, but then again I live in Florida, and it doesnt really get that cold here.

 

[tylerrocks]

I dont think an engine should use a quart a week even with 'low tension' rings. I suspect that guy may not have been totaly honest with you.

 

[Roland69]

I'd use 10W-30 or 10W-40...

I use 10W-30 in my car and in my truck I use 10W-30 in the warmer weather and 5W-30 for the winter

 

[8950HO]

Low tension oil rings .

A lot of these cars were heavy oil burners from the factory including mine.
I had the engine rebuilt under warranty because of this.

 

[conv91lx]

Just a guess, if it's still fresh from the rebuild, the rings my not have set. Don't know much about those low tension rings though. I do know some newly rebuilt engines will burn some oil. In your case I have my doubts about my theory.

 

[aleborjas]

try 15w40

 

[sgarlic]

15 is pretty harsh at startup in cold temps. I took a trip to the grand canyon last fall in my ZJ (with 20w50 in it) and could barely crank it over one morning when it was 30ish outside. Unfortunately I lose hot idle pressure with anything less than 50 for the second number, so I am SOL.

I'd probably prefer a 5w40, although I've heard that the bigger gap between viscosities usually means it'll shear down to a lower viscosity more quickly.

 

[sjhm9102]

try some lucas oil stabilizer

 

[LEE93COBRA]

A lot will depen on your bearing journal clearances. Seems to me that 20w50 could starve the crank of oil unless you have a lot of clearance in the main and rod bearings.

I also believe there is something else going on besides the rings, I had low tension rings over the course of the last year in my cobra (just built it and put standards back in) and my car did not go through oil like that

 

[seijirou]

Try pulling the PCV valve out of the back of the lower intake for a week, cap it off and see if you're still losing the same amount of oil.

These motors are notorious for sucking gobs of oil through the pcv sometimes.

There's no harm in leaving the hole in the back of the lower intake open for a week. At worst you might get a slight oil film on the engine from oil evaporation.

 

[HISSIN50]

Just as a side-note: it seems to me that the PCV being open at the lower intake can cause a vac leak, which can screw with EFI.
Excessive PCV oil passage should be readily seen and noted already (if a baffle was missing, etc).

 

[seijirou]

With the PCV actually not plugged into the lower intake manifold the only other location you could draw air from the crankcase would be through the port vaccum connection between the TB and the valve cover.

In my experience testing port vaccum here, it pretty much doesn't draw any, additionally, the passages between the crankcase and the top of the head are constantly plugged with oil, which is too heavy to move out of the way for air anyhow.

With the PCV installed, pulling out the oil dipstick tube can cause a vac leak sometimes though. Perhaps that's what you were thinking about?