oil pressure????

mike4089

well got my clutch all straightend out drove the jeep down the road for the first time and it shifted nice and smooth.....however the oil pressure was bothering me....when the motor is cold it has plenty of pressure at first start up 65 lbs.....as soon as it warms up it gets very very low....when you rev it up the oil pressure increases but no where near to what it is suppossed to be......any ideas on what can cause this would be great......

Mcktiger74cj5

i got the same thing going with my 304. cant wait till my 360 is done maybe june.

jeepsr4ever

When you have a situation like your describing you can have tight bearing tolerances but poor oil pump tolerances. It is also possible that your sending unit is bad, that also follows those symptoms. Try the sending unit and a new oil filter (WIX preffered), midplate with rebuild kit second and lastly if it still isnt fixed try a new timing cover.

ironman_gq

is 55 cold and 15 hot idle 35hot cruising ok or should I be looking to bump it up?

mike4089

jeepsr4ever wrote
When you have a situation like your describing you can have tight bearing tolerances but poor oil pump tolerances. It is also possible that your sending unit is bad, that also follows those symptoms. Try the sending unit and a new oil filter (WIX preffered), midplate with rebuild kit second and lastly if it still isnt fixed try a new timing cover.

its a direct gauge.....what about the little plunger inside the oil pump stuck open????.....new timing cover???....what goes bad on the cover that will cause that........

jeepsr4ever

Sometimes break in lube or vaseline gets behind the plunger and can cause strange issues. Take the spring and plunger out and clean them and re-install.

dbesade

ironman_gq wrote
is 55 cold and 15 hot idle 35hot cruising ok or should I be looking to bump it up?

Thats what my 304 turns out. 20PSI on hot idle after an oil change... generally its around 15-17psi idle. FSM says at least 13PSI at 600RPM 37PSI min above 1500.

-Dave

mike4089

what about cam bearings????......this motor is brand new..........

jeepsr4ever

Hard to say what condition your cam bearings are in I dont know enough information about the break in temp, time of break in or mileage on the motor.

mike4089

there is like 1 mile on the motor its only been started a handful of time.........

jeepsr4ever

Are you using a old timing cover or a new one? sounds like you may have excessive clearance in your oil pump.

mike4089

it is an old timing cover............what exactly should i buy for the oil pump.....i do know that when i put the gears in for the pump and put the plate on...you could see where the gears rode on the plate but it didnt seem to bad.........

jeepsr4ever

Sounds like you need a basic oil pump/timing cover to fix your pressure woes.

mike4089

what role does the timing cover have in the oil pressure...?????i know the pump gears ride inside of it but other then that what goes bad in them......?????

82Waggy

The inside walls that the pump gear wipe past get worn or scored, opening up gear clearance and reducing pump efficiency. Gear end clearance is also critical to pump performance.

jeepsr4ever

What happens is that the pump cavity itself wears out. It is made from a high silicone aluminum that can wear rapidly due to the oil getting to the pump before it gets to the oil filter. This is the basic issue with these AMC pumps. We are battling this issue with a ceramic coated oil pump housing (thats in the future here) and with our nickel plated oil pump housings. the Ni helps out alot and we are making our own pump using a removable pump as an update to the nickel unit however it is many months away. When you take your oil filter adaptor off check the see how far the edge of the gear is from the pump cavity wall. Using a spark plug shim set you shouldnt be more than .005". If you have greater clearance than that you should look to a new or used pump housing.

mike4089

yay...i found my problem......the small oil gear was in the pump upside down.....gonna put it all back together today and hopefully that should solve my problem...........

Goose

upside down? :shock:

82Waggy

mike4089 wrote
yay...i found my problem......the small oil gear was in the pump upside down.....gonna put it all back together today and hopefully that should solve my problem...........

Don't think there is a difference, unless your original gear is worn on one end.

You mentioned you could see where the gears rode on the cover plate. Assuming you mean the oil filter adapter, you should use a honing stone to smooth the surface the gears ride on, or better yet, install the stainless mid plate that Bulltear sells (smooth the filter adapter in this case too for a good gasket sealing surface).

Since you are seeing this kind of wear, chances are your gear end clearance is loose. If you can see wear on the end of the gears, either change them out or clean them up and set up proper end clearance. If the timing cover cavity walls are worn, you need a new timing cover.

mike4089

the timing cover housing was in really good shape....there wasnt any wear or movement on the gears....the adapter plate had some scoring on it but its not really all that bad.....the oil gears have the two dots on them that are suppossed to be together....one gear was upside down im guessing the dots are there to for a reason....we will find out when i put it all back together i guess..........