Hi, this is my first post and I would appreciate any help if it means I can save money. I'm a working college student who inherited a '98 Explorer (4.0L SOHC and 95k miles)from my family. Two big problems came up within 6 months of me owning the car.

1) ROUGH IDLE AT START - After 10 seconds or so, the engine revs up the RPM to 2,000 and falls.It stalls sometimes unless I keep my foot on the gas or drive it right away to warm it up. This happens in the morning or when I don't drive my car for awhile, but not during the day when the engine has already warmed up. It's not the mass air flow sensor, I believe,because I used a remanufactured one from Autozone but returned it when I still got the rough idle. I sprayed CRC mass air flow sensor cleaner on the old one and put it back on.

I researched and found that many Explorer owners had the "oom12" problem -plastic intake manifold, bad gaskets, worn-out O-rings, tensioner. Which of these need replacing and how do I know if the intake manifold is cracked? Can I replace just the gaskets and O-rings and continue driving with the original manifold? The Ford service repair place wants to charge $800-1000 to replace the entire manifold and I can't make that in a month while at school! Should I go to an independent repair shop? How much will it charge?


2) My car makes a "groaning" noise when I steer in either direction. Going at slow speeds with the windows down, I can hear the car go "GRR" when I go slowly. Not sure if it does this at high speeds due to wind noise. The Ford service place said I just need to get new steering fluid into the system. It charges $88 to do the job with the engine on and injecting fluid little by little.

I've heard that I can use a turkey baster and put in Mercon IIImyself but for $88, is it worth going to the dealership to get it done better? Could it be the fuel pump, steering pump, bearings, anything else??



-- I don't know much about cars except for the research I've done online. Let's say I pay the dealership and the problem reoccurs. Can I contest this and use that money as credit for another fix? Are the two problems I mentioned related? How much will they charge to see to diagnose the problems to be certain what needs to be fixed? I know very little about cars and have to pay rent. Please help out a starving student, thanks!

 

Any 'unmetered' air entering the intake can cause a CEL/DTC's,or cause an unstable idle especially cold.. Ford has had problems with the intake o rings leaking cold and will at times seal on a heated engine with normal expansion.. There's a TSB in regards to this issue.. Could be the IAC (idle air control) as well, if raising the idle 'slightly' when cold will eliminate the stall and/or stumble.. Other causes can be PCV over spec flow/vacuum leaks on the smaller lines ect.. But if the concern corrects itself with a warmed engine, and with the known issues with the o rings it's a direction to look.. Although not rulling out the others, if it follows a 'regular' heating/failing pattern it may be the seals.. IAC issue maybe a 'bit' more irratic or intermittent, but should be in the diagnossis for a possible cause.. The manifold can be leak tested with smoke or propane, smoketo look for leak points, propane for running/data changes witha scanner prior to any repair/replacement.. The composite manifolds for different years/applications have had some problems, but on a limited budget could be checked for flat/damage and reused.. You can understand Fords (or any other manufactures) liability for the not only the repair from the warranty stand point,but safety, especially on higher mileage units that have been exposed to continuous temp changes and age.. I've seen the 4.6 intakes split at the first runner/crossover at fairly low mileages, and other just fine well into the100K ranges..

The steering growl/whirring is most likely the P/S pump, but at 95K the system would need to be flushed anyway or should, and may help with the issue, ora satisfactory improvement.. Reason being, that fluid shear/heat can break down lube oil viscousity.. But If a flush makes no improvement, then replacing the pump isn't really much more work, meaning having to 're-do' any work already done.. If the system has/had any leaks and the pump has run dry, then the pump could be damaged.. Any reputable shop shouldnot only stand behind their diagnosis and/or work with you, but the repair as well.. But should also point out the possibilities (plural) as to cause/s, and give you an informed 'advisory' as to varing costs...

 

Hayapower, thank you for the quick reply and great information.

For the intake manifold problem, I think I'm going to wait it out until the summer and let my family take care of that. The expenses are too much for me to think about at this time.

As for the steering growl, would it be better for me to change the steering pump and do the flush at the same time? Or should I do the flush first and see if that corrects the problem? How much should I expect to pay for a new or remanufactured pump? And for this simple fix, should I take it to a dealer or cheaper repair shop? I forgot to mention that the steering fluid level looks good so I don't think there is a leak. The color looked a bit dark so maybe it is contaminated? I'll check again tomorrow.