Looking for some advise. Have a 98 Explorer Sport 4.0L EFI. When I start the truck it idles a little rough. But if I drive it right away the whole truck vibrates because the motor is bogging down. If I let the truck idle for a few minutes before driving there is no problem. If I do drive it right after start up it bogs down for a few minutes then smooths out and runs fine. I have replaced the plugs and wires. Cleaned the MAF, and replaced the idle air control valve. Maybe the TBS is bad? Any suggestions to my problem would be greatly appreciated.

 

I started a similar thead this morning - mine is a 98, 5 liter explorer. I get knocking or pinging until it warms up. Then, the problem almost or completely disappears until I turn the engine off then it comes back again until I run it atleast 30 seconds again.... sometimes longer. I cleaned the MAF, and replaced plugs. Since the plug wires are due, I will change them, but I doubt that this will fix the problem, since this thing idles and always runs smooth after a short warm-up....... I suspect the EGR valve, but will do some more research before doing any more tearing into this.

It does make sense that a sticking valve would tend to produce this behavior...... Everything else that I have read about, seems to get worse as the motor runs - fuel injectors, filters, pumps.

Not sure about the TPS or the profile ignition sensor.

Good luck with yours.... please let me know what how it goes.

 

had this prolblem it is your lower intake manifold gasket make sure you get them fized under recall

 

Billy - I have read about the gasket in the past few days. When I first bought my explorer, (used) a month ago, I had the Ford dealer check out the AC. He did not mention this recall...... should I be surprised?

Today I did a quick visual check of the tubes and hoses around the EGR valve....... sure enough, there was a crack in the tube that leads to the EGR. As a quick test, I used JB Weld epoxy on that area, waited 15 minutes, then went for a short but brisk test drive. Knocking/Pinging were virtually gone. Looks like I found at least most, if not all, of the problem. But I plan on calling the dealer back to ask why he didn't mention the recall.... or how broken heater box plenum doors produce a symptom of a bad AC system (I have tried the "free (AC) fix" - it works).

Thanks for the info.

 

There are many "not talked about" recalls on explorers. They do not tell you unless you complain about a problem related to the SB recall.

 

Michael what is a SB recall. Billy there are no recalls according to Ford for my vehicle except a bolt for the reclining seat ( 98 Explorer 4.0l EFI). If you are right though how can I tell if my lower intake manifold gasket is leaking? Also if it was wouldn't it trigger a sensor and thus a code?

 

Ford Service Bulletin.
If I can remember a few:
Cam noise.
Torque Converter.
Lifter Noise(might have been part of the cam)

Did they run your vehicle on the old OAISIS system?(for recalls)
Ask your Service Advisor about the intake manifold gasket, then talk to the Service Manager if unsatisfactory result.

NHTSB.gov carriers complaints and recall information.

 

Have a 96 explorer, I start the truck, runs rough after about 30 seconds to a minute, it smoothens out and runs pretty good. I have a check engine light that is on though.

Checked out the code says 1 and 2 misfiring. Did a compression and compression came back 120 at first dropping to 0, but I get good milage per gallon, runs fine?

I am going to to a leak-down test, and a motorvac treatment to see what is going, and hope for a cheap miriacle. Point is you could have a valve, head gasket, or cam issue, or I could be looking in the wrong area.

Just a though, the issue seem the say.

 

Could the timing chain tensioner be my problem?

 

Could my timing chain tensioner be the problem?

 

Michael013

What is the torque converter service bulletin you mentioned. I didn't know about the lower intake manifold gasket bulletin, and will have that checked out. I bought my 98 sport 2 years ago with 34,000 miles and the pinging started around 40,000 miles. I've just been pumping higher grade gas into it and that seemed to help. It also bogs down when I first start driving. I have 71,000 miles on the truck now.

 

I think the LIM gasket recall is only on the 4.0L SOHC, does not include the 5 liter.