Hey guys,
I have been doing a lot of work on my bronco lately and I just finished doing the fuel and oil pumps. I had new exhaust put on today and now that I am able to drive her again after almost 2 weeks of sitting I have little or no power when I step on the gas. It hesitates and then kicks in with less than half the power it used to. I have noticed one thing that scares the hell out of me. When I drained the oil to do the oil pump I noticed a metallic look to the oil. I am hoping that the oil pump going bad didn't do any major damage to the engine. I kept the driving to a minimum once the pressure dropped on the gauge but I was a good 10 miles from my garage when it went out. Did I ruin either my crankshaft or camshaft bearings? The reason I ask is because I lost oil pressure today after the truck warmed up but I think that I know why. When I was taking out the oil pan the exhaust Y pipe was in the way. When I tried to remove it from the manifold the bolts would not budge... even with some penetrating oil and an impact. By process of elimination we came to the conclusion that the cut Y pipe could be boiling the oil in the pan and causing it to lose pressure. Hence the new exhaust I had put on today. I haven't had a chance to drive it to full temp. since the exhaust upgrade because I had to get home so my wife could go to work. After all this work, why no power on the pedal? Timing? Distributor? I can't afford for those bearings to be shot on either the crank or cam shaft. Why else would it lose pressure after installing a brand new oil pump? Thanks in advance.

KJ

 

[updated:LAST EDITED ON 08-Jan-03 AT 09:20 PM (EST)]Unless the oil was heated to a point that it is no longer maintaining viscosity, the only other reason I can think of for losing oil pressure is increased flow through the system which is generally caused by oversized gaps (i.e. spun bearings). I would drain the oil thats in there and see what its condition is. Try again with new oil if you have to but it doesn't sound happy. The metallic colored oil is a scary sign. This Bronco owner had a Cherokee when he was young (and more stupid) and I lost an oil pump check valve and only drove two miles and it still ruined mainbearings. Here's hoping your theory of overheated oil is indeed the case. Spun bearings or scored cylinders will rob power in a heartbeat. Just one question, how much oil pressure did you lose when the pump first showed signs of failure?

 

When the pump first went out my suspicion was that the sending unit next to the oil filter went bad. So I replaced it to no avail. After that I put a manual gauge on it and could only muster up decent oil pressure at around 3500rpm which is bad being I can run 65mph with less than 3500rpm. Anything under 3000rpm was pegged low. Beyond that I started on the oil pump. Is there anything else I should be looking for to push me towards having to replace those bearings? What a headache.

KJ

 

The exhaust doesn't get hot enough to boil your oil. If it did your pipe would be turning red!!!