96 Explorer - Help!

[Junia]

Hello all,
First off I have to say that I have spent a lot of time on here, great info! That's why I am hopeful someone can help me here.

I have a 96 Explorer, 4.0L V6. It has had a rough idle at startup for a while, which will even itself out after warmed up. Recently the temperature gauge started moving from around the center to "C", up and down slowly.. never overheats. This afternoon the check engine light came on.

RECENT WORK DONE
My husband did tune up (new plugs, wires, pvc, air filter, etc.) then we replaced the MAF sensor. We thought it was fixed, so started on a trip, 200 miles in it starts squealing, similar to a whistle. This is when we noticed the temperature gauge fluctuating. We of course, came back home.. changed the thermostat, water pump, 2 pulleys (idler pulley was the cause of the whistling), and finally the fan clutch. Temperature gauge still moves!! and today the check engine light came on. The idle when you start it has greatly improved, however it still starts choppy on occasion.

Any help anyone can offer would be sooo appreciated!!

 

[my98nnj]

1) What engine do you have?
2) What were the stored DTC's?

If you have the SOHC engine, the idle issue could be intake manifold gaskets.
The temp gauge issue could be a poor electrical connection. Why did you replace all those cooling system parts without further troubleshooting? The engine wasn't overheating, seems all you had wrong was the idler pully. Everything else could have been verified before you started replacing parts.

If the check engine light is on, pull the DTC's and post them up here so we can further assist you in troubleshooting. You can go to your local Autozone and have them scan for DTC's usually at n/c. My guess is you have a lean condition - pointing to the intake gaskets IF you have the SOHC engine.

 

[Junia]

ok well first of all, the tune up and maf sensor were replaced in readiness for a trip. as for all the coolant replacements, the idler pulley grinded something fierce...and with all the gauge play and leakin a lil coolant.. we along with mechanics.. assmued it was the water pump, when that obviously wasnt it.. we replaced the thermostat in hopes that may or may not be it. keep in mind at this point there was no CEL yet. the fan clutch just happened to be failing as well. and we would get a code however, autozone & oriellys dont test on cars older than 2000. we dont know the DTC. and its a 2 wheel drive 4.0 im not sure if its sohc or not.

 

[Joe Dirt]

If that's true and they aren't going to test vehicles older than 2000, I would invest in a cheap code reader if you plan on keeping the truck. You can get pretty nice ones on eBay for $30-$40...

I'm also on the intake gasket thought- I know when a mechanic says "yeah, I'm pretty sure this is it" and you just want the d**n thing fixed, it's tempting to say yes and get it done, but if you can- bring some info here before you buy parts because we might be able to save some $$. I'm sure the MAF and water pump, etc... wasn't cheap.

 

[ahodges]

These trucks only came with a 4.0 OHV or a 5.0 V8 in 96.. They didn't offer the SOHC until 97..

The gauge fluctuation is a common problem on these engines and there is a service bulletin about it..

 

[Junia]

yeah we did all the work ourselves to save money, and spent a fair amount of time reading on here as well for help. we plan on buying a code reader just having had the time yet. we'd love to have one. i read the service bulletin on it... the conversion kit runs roughly 200 bucks. theres no way we'll be doing that. we truely think at this point it could be the heat sending relay? not sure if that the correct name. but if i understand correctly if its malfunctioning at start up, it could send an incorrect fuel amount to the fuel injection? this is a great running vehicle to this point and still runs like a champ. just this issue of jumpy gauge & the start up roughness.

 

[Junia]

First off, thank you guys for all your input. I wanted to follow up.. we got the code from the computer.. P0402 - Exhaust Gas Recirculation Flow Excessive Detected. So I've done some research on here and see that there are a few parts to the EGR system (hope thats the right term).. Anyone have any pointers, ins and outs, or don't do this's before we plunge into this?

 

[swetrid]

DPFE sensor is probably bad and it will make it run rough.