Yep. I've got some weird stuff going on again -- or I should say "still." I've chronicled some of the lengthy repair history of my POS 3.0 here in the past, but to summarize the latest...

My 2nd engine exploded due to a failed oil pump while climbing a steep incline at highway speeds. It was spectacular, actually. My 3rd engine was subsequently bought as a remanufactured engine and installed with all the goodies you'd normally replace during a swap -- water pump, timing belt, knock sensor, etc. I have since had a long and so far unresolved history of over heating. The engine overheated and blew the head gasket again last fall, cracked one head and warped the other beyond spec. Both heads replaced.

I got it back, but it has never seemed right since this last repair. The valves are ticking louder than I remember, and after putting about 1,000 miles on it I noticed the oil pressure was running low after the engine has warmed up. About the same time I also noticed that the engine would make a faint deiseling noise when it is under load (like going up hill). This has become progressively worse and its starting to give me flash backs to when the oil pump failed on my 2nd engine and it blew up.

To top it off, I can't get the temp gauge to remain steady to save my life. Granted, it's way hot out here right now, but my other 4Runner manages to run cool regardless of how much I run the AC or stop & go traffic I encounter. On the Epic Mobile, the temp gauge starts to climb under any stressful condition but never moves past the 3/4 mark.

These may very well be two seperate issues, but I thought I'd mention both in this post. I'm more concerned about the low oil pressure and deiseling under load. Any advice on WTF could be the problem, or where I'd start looking to diagnose it myself?

Ed

 

Beuhler? Beuhler? ... Beuhler?

 

The diesel noise your hearing is probably pinging... If your engine is running too hot this will happen.

Have you flushed your radiator? Have you flushed the system? Have you gone with a new OEM Thermostat.

 

Sorry to hear of your latest fiasco Ed.

Time for a 3.4 swap? I know you have put more money than you want to think about into your engine repairs.

 

Yeah, I started pricing out the 3.4 swap. It's just not practical with an automatic tranny. You're looking at $5000 in parts/engine and that includes nothing for labor. I might be able to do some of the work myself, but not the whole project. It's just too expensive for me to do at this point. So, I'm probably going to pull this engine and rebuild it from the ground up.

The deiseling isn't pinging -- different noises, and I know what you're talking about. This is more of a low-end rumble like it's struggling to provide power. Like if you're heading up a steep incline while driving a manual tranny and you don't have it in a low enough gear.

I'm probably going to pull the radiator next. It was brand new as of 5/04 with an extra row added so I haven't suspected this as a problem, but its worth looking into. Thermostat has been replaced several times in this process -- cooler temp thermostat was tried, went with a dual stage, and now am back to an OEM. It's not the thermostat.

Ed

 

Well if its OEM thermostat should be ok.

OEM temp though is 180 compared to the usual 190-195 tstats. I've tried finding a cooler t-stat, I wouldn't mind putting a 170 in it, to help bring down the temps a little bit I can't find anyone who makes a 170 tstat. 180 is the coldest I can find and thats the OEM spec'd temp.

Only thing I can think of is your radiator or fan clutch isn't doing its job like it should.

Your not throwing Check Engine Lights or anything? Does your CEL work?

 

No CELs. Fan clutch replaced twice and now has a heavy duty fan clutch. Found the 170 degree thermo on eBay.

I'm going to give the radiator a flush and possibly try to upgrade it. Other than the water pump, which was replaced when I got the 3rd engine back in 5/04, there's nothing other than basic air flow that affects the temp of the engine -- that I'm aware of. I did recently mount a tranny cooler in front of the radiator, but it was doing this fluctuation before I added it. I'm sure it hasn't helped, so I'm going to find another place to locate it and maybe install an additional electric fan in that space.

Ed

 

Did the 170 degree thermo effect anything? I've been reading the FSM and it seems certain functions come on after 170, but the ECT, (engine coolant temp) mod tricks the ecu into thinking its slightly cooler to inject a little more fuel for more power.

 

I had problems with my tranny -- the temp gauge has to be at a "warm" temp for the transmission to go into 4th gear and since I installed it in the winter (still mild for us) I'd have to drive around a while before the transmission was hot enough to use all gears. It became annoying so I changed it back. I did not notice any performance improvement at all.

Ed

 

Just an off the wall test, Pull and plug the vacuumline to the Fuelpressure regulator and see how it drives after that.