i got my truck back yesterday after getting the head gasket fixed and it was driving fine but after about 15 mins i noticed the oil pressure had dropped off and the oil light was on the engine was running fine and had no loss of power or nothing just the guage dropped to zero and the light came on also i know that the tiny vacuum hoses are shot could that be causing the check engine light to come on as well as the oil pressure situation im going to go to advance and have them check the codes for me later today or tomorrow

 

if you have the digital odometer, do the key on - off - on - off - on thing and it will display the codes.

i would not drive it w/o oil pressure. it could be a faulty sending unit and your pressure is actually ok. or you could have a clogged up pickup screen or something and have a real problem. i wouldn't take that chance.

 

so how would i check the screen drop the oil pan and then clean it out or what and is there anyway to check the oil pressure other than pullin the valve covers

 

First thing I want to say is this. Nota put down to you, but check to verify that there is enough oil in the engine.

Next check your oil pressure with a mechanical oil pressure gauge.

Remove the electrical oil sending unit (at the rear of teh engine to the left of the distributor), and connect your mechanical gauge. Start the truck and watch the gauge. If you see oil pressure at idle, you can rev the engine a little to watch the fluctuation in pressure. If no oil pressure you've bigger problems. For about $60 or $70 bucks you can install a brand new High Volume Melling Oil Pump and pickup screen. The oil pan gasket is a re-usable rubber one so you do not need to replace it unless you damage it.

If you have oil pressure on the mechanical gauge, the problem is with your sensor or the electrical connection to it. First attempt to use some di-electric grease on the connection and re-install your original sensor. If still no pressure, replace the sensor.

Hope this helps.

 

thanks that actually does really help me i bought that engine restore stuff they were talkin about on here earlier and the guy didnt put it in but would low oil cause the pressure to drop then come back then drop again? it doesnt drop during acceleraton just at random times but ill check the oil level and then clean the connections you were talkin about thatnks again and if i add that engine restore stuff to the oil like it says is that on top of the normal 6 qts or or not because i really dont wanna have to much in there to help kill my already bad mpg

 

It's always best to only fill your crankcase to the recommended maximum line. Too high and your crankshaft can hit the oil causing it to foam and that will cause air to enter your lubrication system which is not a good thing. So if you are going to use the engine restore stuff, use it to replace an equal amount of oil.

Since you did recently have the head gaskets replaced, it is possible that you have some gasket garbage floating around in your engine and pan. This can block oil passages, clog the oil pickup, and even prevent your oil sending unit from receiving the right amount of fluid so it can reflect the right pressure. Did he change your oil after doing the head gasket work? If not I'd recommend you do it before deciding to pull the pan. If it isreally full of crap, you needed to drain the oil anyway to replace the pump and pickup so you're one step ahead. if it only a little full of crap, then changing the oil may solve your problem.

Good luck.

 

i checked the oil just now and the oil level is a little (1/4 inch) over the full line but on the bottom of the dipstick was about
3/4" of black somethin (sludge?) if it is sludge could i get away with purin that engine restore stuff down in it after i drop the pan and scrape it all out?

 

If the dipstick has sludge then you definitely want to drop the pan and clean it out. Chek the oil pump pickup screen also and clean it if possible. If not you're going to have to install a new one. If the gunk was thick enough you may have pumped it into your oil pump and cracked/ruined it.

Before pulling the pan, do the hydraulic oil pressure test first. Wouldn't want to have to pull the pan twice if the pump is bad. No matter what, you need to get the oil pressure back up before getting too gung ho about cleaning the inside.

If you don't need to replace the pump I would recommend putting a quality detergent oil in along with a quality engine cleaner (maybe your engine restore stuff does this). Run the engine for a little bit and drain it again and re-fill with fresh oil and filter. You may need to do this a couple times before cleaning the crap out of your system.

An old school trick was to use 1/2 quart transmission fluid in place of the oil. It has a high level of detergent and worked wonders for cleaning oil passages and such. Sometimes you had to do it a couple times also, but with the improved products on the market you can find some engine cleaner that'll do the job.

 

the guage shows normal pressure when i have oil pressure could the pump still be bad?

 

If the pump was bad, you wouldn't be getting pressure. But what do you mean by "when I have pressure"...if you installed the mechanical guage like turkeyhunter suggested and you loose pressure every now and then, you have a blocked passage or bad sending unit.