Chemical fix for low oil pressure due to crud in oil pickup?

[LTDScott]

I have an 85 Ford LTD with a 94 Ford Mustang 5.0 engine installed. I recently changed cylinder heads with aftermarket ones (AFR).

Long story short, my oil pressure dropped severely after the head swap. I'm down to 5 psi at hot idle and 35 at hot cruise. I made the mistake of not changing the oil before I started the engine, and I think some of the old head gasket crud got into the engine and got picked up by the oil pump pickup.

The engine has about 140K on it and was fairly clean (see pic of valve cover below), so I can't think of anything else. I've changed the oil and filter twice since the swap (including using straight 40 weight oil) with no change in pressure. I also cut open the filter I used after first starting the engine and found no metal.

I was recommended to this board by people on a Mustang board for a possible chemical cure to my problem. Dropping the oil pan is a $500 affair, so I'm open to any suggestions. I've heard good things about Auto-RX, but I think it would work too slowly for my purpose. Any ideas?

Thanks,
LTDScott

 

[AV8R]

I doubt that your oil pickup is clogged. You may have a stuck-open oil pump bypass valve, though. That's a pan-off job. Most likely, the heads may be at fault. Take off the valve covers, one at a time, and crank the engine (ignition unplugged, of course) to see if you spot a gusher.

 

[Frank]

Your engine is a good candidate for Auto-Rx please revisit www.auto-rx.com and click on "Instructions" your type problem is common and is what Auto-Rx corrects

 

[Motorbike]

Scott , Welcome to the forum .

It's been many years since I've been inside a 302 but if it uses a o'ring around the distributor shaft and it's missing or damaged it will drop the oil pressure from loss at the cam area . Alot of the after market distribs have this feature and must be used on the early Chevy V-8 even though the factory distib came without . I also think you could have damaged you oil sending unit , easily done when removed .

I've seen some very dirty engine work in my life but never seen an oil screen clogged from gasket material . Always the first time though but check oil pressure with a manual gauge first and go from there .

A distant possibility and very distant if if the head gaskets are on wrong and not letting the oil drain back ... deal there though is the gauge would fluctuate " so would a partially blocked screen " so scratch that idea

It will not live long with that kinda oil pressure if you run it hard so my advice would be 40wt and engine idle only until problem is found .

 

[LTDScott]

Hmmm well I was looking for a cheap fix but I don't think I'll find one. I'm pretty sure I'll have to pull the pan one way or another. That basically means pulling the engine. Ugh. Sometimes I hate cars.

The only other possibility I can think of is that there was some coolant in the oil and that possibly wiped out the bearings. I really hope that isn't the case.

 

[Motorbike]

Alot of glycol will kill the bearings quick . Seen many a Chevy with as simple as intake manifold changes spin even the main bearing because of glycol .

FWIW newly built engines should be initialy fired on water alone .

In one of the Chevy V-8's the hydraulic roller lifters from another will physically interchange . One is shorter than the other though and will result in ZERO oil pressure because of pressure leakage .

Are their differences in this respect with the small block Ford .? If so , it's a real possibility if you changed the cam but did not post.

This topic going to get moved

, you might go ahead and try Auto-RX as a cleaner but sorry I can't help further with this...your engine is not here

But I would put a mechanical guage on it first as a diagnostic test .

[ April 02, 2004, 11:08 AM: Message edited by: Motorbike ]

 

[Terry]

Auto-RX will NOT clean head gasket material if that is what you are sure is blocking things, drop the pan and physically clean the pick up.

Use the sage advice from the previous posters to make sure indeed the pressure is truly low BEFORE tearing things down.

If you have low pressure and its gunk the RX will clean fast enough to save the engine.

Terry

 

[novadude]

Hmmm... what about the distributor O-ring? Does Ford have an oil gally passage in the distributor body like Chevy? Does the o-ring seal it? Maybe the o-ring got torn on install?

BTW, LTD... glad you found this forum.

 

[LTDScott]

Motorbike, I am certainly afraid of toasted bearings, but the signs (so far) are pointing to other things. Cam/lifters were not touched. I primed the pump with a primer tool before I fired up the engine and had good flow to all the rockers. The car has a Autometer mechanical gauge on it already (this is what tipped me off the the problem) and I actually bought a cheapy Sunpro mechanical gauge to verify that the problem wasn't the gauge (or tubing or fitting). Both gauges show low pressure.

Novadude, the distributor does have an o-ring, but I don't believe it has anything to do with pressure. It simply seals the oil from seaping out of the distributor hole on the timing cover.

If pulling the oil pan was an easy job I would have done it a long time ago, but unfortunately it requires pulling the engine, or at least lifting it up really high. I'm supposed to be taking this car to a show 2 weeks from now, and next weekend I'm taking a trip to the Grand Canyon, so I'm kinda screwed as far as time goes anyhow.

 

[novadude]

I wasn't sure about the o-ring... I am new to Fords.

 

[rbraughn]

LOL at Auto-RX Frank.... I think if someone posted they had arthritis, he'd pop in and say they were a candidate for an AUTO-RX treatment.