Strange oil pressure problem

[jackndelphine]

Hey everyone, great forum. I just got a 88 Grand Wagoneer with a 360 for free because the guy said the motor was shot and had no oil pressure. Well I started it up and played around with it and at start up it had about 80psi and after about a minute or so it dropped to around 40psi, then after another minute or two it dropped to about 10psi, all the while the engine still hadnt reached normal operating temp, only about 110 degrees, so naturally I saw the drop in pressure and heard the enegine start to make a little bit of noise, I shut it down, and just for the heck of it I started it right back up not even 30 seconds after shut down, and I looked at the pressure guage and it was right back at 80psi again, now it doesnt matter if it is warmed up or not, it almost always does this. Do you think I might have crud in the oil returns in the heads and the oil isnt coming back into the pan quik enough, or maybee my pick up is clogged, or could this be some kind of common problem with these trucks?? I am going to pop the valve covers off tomorrow and start digging in, I hope I will be going in the right direction.

Thanks in advance everyone, Jack

[jeepsr4ever]

Jack welcome aboard :t: I would look at the oil filter adaptor and sending unit first. Occasionally the plunger will stick if it has worn a groove or if oil has sat behind it and thickened. Take the large 7/8 bolt off the oil filter adaptor and take the spring and plunger out.....if you can. clean them and re-install and check the pressure once again.

[jackndelphine]

Thanks for the warm welcome, unfortunatly, I didnt see your e mail untill just now and I had already pulled the valve covers off to check the valve seals and the oil returns in the heads, I stuck a coat hanger down the returns to see if they were plugged and then blew compressed air into them as well. Tomorrow I was going to drop the pan and check the screen on the oil pump but I will definetly check out that thing you said about the oil filter adaptor before I do anything. Ok well I will let you know what I find.

Thanks, Jack

[Lifted79CJ7]

OK, step off! I had that name first!! J/K! Welcome aboard!!
8)
The Other Jack (Ha ha ha - OJ)

[jackndelphine]

Ha ha Jack!! Hey I think I solved my oiling problem, I pulled the 7/8 bolt off and out popped the spring and the plunger, actually the plunger first then the spring, #-o I inspected it and cleaned it up a little bit, and then I realized that it was in backwards (I think) The spring was in first and the plunger was kinda in the seat of the 7/8 bolt. So I put it together the way I thought made more sense, and started the truck and the oil pressure gauge was pinned over 80lbs, and the valvetrain was nice and quiet. I let it run for about an hour or so, revved it up a few times and the pressure never dropped below 60lbs, and when I hit the gas the pressure went up. So I am guessing I solved the problem?? I will put it on the road next week and begin driving it so i will see if it is gonna work out, now all I have to do is figure out why my tailgate window won't roll up and down.

Thanks for the help, Jack

[Lifted79CJ7]

Sweet! Glad it was an easy fix! So ya have any pics for us of this beast?

Otro Jacko

[Goose]

Here Now!!.. Dammnit! It was my turn in line for a sweet purchase/easy fix.. you cant just come in and and use up my turn.. I had my eye on this sweet Ferrari Testa Rosa that had a bent rotor in one of the distributors..


Seriously.. Welcome and glad to hear you got one of the easy fix freebies!

[tarior]

Welcome, and congrats on the excellent freebie! =D>

[jeepsr4ever]

Priceless :mrgreen: I am happy for you...nice find!

[Mudrat]

We're still waiting on pics!!! :smile:

Ya just can't waltz in here, solve your problem and dance away :shock: I just ain't right 111!!!

[jackndelphine]

Yea, sorry about that, I will have to take some pics tomorrow, and post them, oh but guess what else!!! I kinda never solved my problem, when I put that pressure releif valve back in, I guess it was ME that put it in wrong, yes, I had 80lbs of pressure and the truck didn't knock, but it also blew 2 oil filters off and shot oil all over the place. So, I had another engine with 40k on it and I changed it 2 weeks ago, it was a pain in the ass but it runs great and has about 45lbs of pressure. The only thing is that it is really hard starting when cold, the chock is working and adjusted properly but I have to pump the gas like hell to get it to start. I am going to look at that tomorrow, anyway I will try to take pics of the rig tomorrow and post them.

Talk to you guys later, Jack

[Mudrat]

Yea, sorry about that, I will have to take some pics tomorrow, and post them, oh but guess what else!!! I kinda never solved my problem, when I put that pressure releif valve back in, I guess it was ME that put it in wrong, yes, I had 80lbs of pressure and the truck didn't knock, but it also blew 2 oil filters off and shot oil all over the place. So, I had another engine with 40k on it and I changed it 2 weeks ago, it was a pain in the ass but it runs great and has about 45lbs of pressure. The only thing is that it is really hard starting when cold, the chock is working and adjusted properly but I have to pump the gas like hell to get it to start. I am going to look at that tomorrow, anyway I will try to take pics of the rig tomorrow and post them.

Talk to you guys later, Jack
Plunger, spring bolt ... you got it right. Now what the heck happend you did the R&R on the motor???