01 Explorer... need advice...

[NOLA_Ken]

I recently bought an 01 Explorer that had "been sitting a while". I drove it for around a month and a half to and from work (around 5 miles there and back) with no problems at all. About a week or so ago as I was going home the engine (4.0) started running rough, overheated, and shut down right as I got to my house. When I checked, the radiator was pretty much if not completely dry. I hadn't noticed any steam from under the hood, and there was no anti freeze cloud from the exhaust, and no water in the oil either.... once it cooled down I refilled the radiator and it started right up. I couldn't find a leak anywhere....

A few days later I drove to work and when I parked I saw steam from under the hood. It seemed to be coming from the thermostat housing area, so I thought maybe it was cracked and that was the source of my coolant loss the last time.... I headed home to see about finding a replacement but in less than a mile the engine started running rough and rattling again... the temp needle was normal, the heater worked, so I knew it wasn't run dry, but then I noticed the oil pressure needle had dropped to zero.... every so often it would jump around a bit, but always just dropped to zero again.

I thought maybe when the engine got hot the first time whatever sludge was in there might have clogged up the oil filter or pump pick up, so I did an oil change, ran it for a minute, got pressure initially but then it tanked again. I'm guessing the oil pump is shot, but what I'm, wondering is if there's any way I can verify that is the problem before I go through all the hassle involved in replacing it. I'd hate to spend the time and money on it just to find out something else is wrong and the engine is junk....

Any thoughts?

 

[puzzaa]

What did the oil look like when you changed it out?
I believe there is a screen in there that can sometimes get clogged up and prevent oil flow (since it sat a while, and would explain why it happens irregularly). I don't think there is a way to unclog it without taking it out and looking. I read an article on putting in carb cleaner and letting it sit for a couple days then draining and flushing with clean oil but it doesn't sound like a good idea to me.
If you want to you can try to get access to that screen but it would be about the same work to get to the oil pump too (maybe try to get one off a junk explorer).
also, the oil pressure gauge on the dash is misleading sometimes, I believe there is a kit you can rent from autozone that will give you a real pressure reading to decide if you care getting no pressure.
And lastly, if it has been running with no oil you could have some problems with your pistons and rods due to running with no lubrication. The engine may not start again or may run rough if somethings been damaged inside and unless you can replace it yourself is going to be big $$, which probably wont be worth fixing.

 

[NOLA_Ken]

The oil was pretty black, it was in need of a change anyway...and there were some chunky bits in it, but I didn't see any metal in it. The screen is just under the bottom part of the pan and will be a whole lot easier to get to than the pump, so I'll look at it next.

From what I've read, the oil "gauge" just tells you if there's pressure or not, so I would assume that being at zero isn't good. I'm guessing the rattle is the hydraulic lifters getting no oil from the pump?

The engine starts, and runs... but with the rattle and the oil needle at zero I'm not about to start it again until I know the oil is moving through it

 

[puzzaa]

If it was sludgy and thick, then it could very well have clogged up that screen. You could do the carb cleaner method (or Seafoam) to try to eat up some of that gunk if thats the case. but Id recommend taking it out and running the carb cleaner through so that way the stuff doesnt end up in the pump and clog it up. or just buy a new screen!

Im not sure about the gauge, all im sure is that they are misleading and faulty at times. Best way is like I said to rent a pressure tester and just get an exact number so you know for sure you are getting good pressure (the dash gauge may read normal when in reality oil is barely flowing, which is probably what was happening at first). the crud probably completely backed it up which caused the needle to drop to 0.

Check that screen before messing with the pressure gauge and if thats the case and you get it running, run it for a couple minutes and then check the oil again. If it still looks clean then do a pressure test. If not flush it again with a new filter and then check the color and run the test.

Hope this helps!

 

[puzzaa]

The rattling could be anything by the way. When the engine doesn't get any lubrication, the metal parts rubbing dry can cause a rattling (especially the timing chains from what ive read up on and the notorious 4.0 Timing chain rattle). So the noise should disappear once you are getting fresh oil in there (unless something broke/bent, which I doubt but just wanted to let you know).

 

[NOLA_Ken]

I'll pull the lower pan in a bit and see how it looks. hopefully it's just the screen on the pick up, I really don't want to have to tear into it to get to the pump

 

[koda2000]

If you have the 4.0L SOHC engine, remove the lower oil pan. You'll likely find pieces of tan/brown plastic blocking the oil pickup and the pickup screen may be blocked by debris and sludge.

The plastic pieces are from broken timing chain cassettes. The pickup may also be blocked with sludge which forms when a vehicle is left sitting with old dirty oil in it.

I'm sorry to tell you that replacing the timing chain parts is a huge, expensive job, because the engine must be removed from the vehicle. If you can't do the repairs yourself, the repair costs may very well exceed what you paid for the vehicle.

Many of us here have learned about the SOHC engine the hard way (including myself). It's a POS IMO.

As far as the thermostat housing being the cause of your coolant leak, that's very likely. The plastic t-stat housings tend to crack and leak w/age.

 

[NOLA_Ken]

well.... I pulled the bottom pan.... found a bunch of plastic shrapnel and 2 flat springs in there with the usual sludge...

anyone recognize this mess?

On the plus side, after I cleaned the oil pick up, it started and ran and had oil pressure again. There was some clacking noise that quieted down after it ran for a couple minutes and the oil had a chance to circulate so at least the engine isn't trashed.

anyway, what was this wreck, and how hard would it be to replace it or just to keep the thing running at least to get to work and back?

 

[david4451]

That is primary timing chain tensioners disintegratiing(jackshaft to crank) and possibly secondary plastic parts ( jackshaft to cam). Don't run engine again, suggest you pull rocker covers and look if front & rear timing cassettes are still there.
It looks like you have not bent the valves yet so you have to pull engine & replace all timing components!
It is a big job and engine out, I suppose it's up to you if you fix it or not?

 

[koda2000]

Yeah, that would be the remains of at least one of your timing chain cassettes and other pieces of chain tensioners. That mess would explain your oil pressure loose. It's possible it's only the front (driver's side) cassette has broken, but without taking things apart the condition of the rear cassette is unknown. If it's just the front, it is possible to replace all the parts w/out removing the engine, but it's still a pretty big job. Personally I wouldn't put the time, effort or money into doing just the front w/out doing the rear too.

Depending on how many miles are on the engine (if you said I missed it), the condition of the vehicle in general and whether your mechanical skills are up to the task, it may or may not be worth fixing the engine. TC problems can happen within as little as 75K on these engines.

As said, do not drive the truck anymore, as it will soon bend valves (if it hasn't already done so) making repairs unfeasible. Any time you hear that a vehicle "has been sitting a while" you should figure there's a darn good reason the PO stopped driving it. Hope you didn't give too much for it.

 

[NOLA_Ken]

I paid 1000 for it, so it's not a huge hit if I can;t get it fixed. doing the work isn't a problem, but seeing as I don't own a hoist or an engine stand, and my house doesn't have a garage it would be a huge pain to do it myself. I guess I'll dig a bit deeper and see if it's just the front of the engine that's let go. If I can keep it running long enough to get another vehicle I'll be happy