99 4x4 XLS low miles with tons of problems.

[eupleili]

Hey there,

This is my first post so I hope that I can get some answers. I have used this forum to fix a number of things on my X and there seems like a never ending list of things that still need to be done. It only has 75k miles on it and I just cant seem to get it to run right. I have three major problems right now that I would love some insight on:

1. I have a very rough idle/cruise at coasting speeds. I have recently replaced my DPFE sensor because it was "torched" by a loose vaccum hose. It ran fine for two weeks and the Check Engine Light actually stayed off for those two weeks. Then all of the sudden the light came back on and the rough running has been getting worse and a sulfer "rotten egg" smell has started. I have read that it could be the cat but more likely the EGR system.

2. I have never really had the type of power/excelleration that I thought would come from this vehicle. I have driven other vehicles of this year and even earlier that have a nice smooth and powerful excelleration. Mine is rough and revs the rpm's before the tranny shifts to a lower gear and even then it just seems loud and rough never smooth.

3. The third problem might be an extension of the 2nd or the culprit. It seems that when the truck gets to around 2.5 rpm's the engine revs verry high. I have planned to change the transmission fluid, filter and gasket soon but I don't know if the problem might run deeper than that.

This weekend I plan to do minor tune-up maintenance such as replace the fuel filter, pcv valve, oil change, and other minor things. I have recently changed all of the plugs, dpfe filter, and the vaccum lines that come from this. I have a full mechanics garage at my disposal and correct mechanical supervision to do all the work I need done I just need some push in the right direction. Thanks in advance for the help and hopefully I can make this beast last for me for another couple years.

 

[XLT]

Welcome

1. Usually clogged cats gives you a sulfar smell. But the best would be to scan for codes.

2. What engine and gear ratio do you have? These are key for power. V6 sohc or ohv, or v8 are the choices. I have the sohc and its a lot quicker then my 93 with ohv v6 was. CLogged cats could be reducing power as well as your check engine light.

3. I am unsure on

Matianence might help as well. Dont forget air filter and to check your fluids as well

 

[1Aauto]

Welcome to the site.

 

[eupleili]

Gear Ratio

It's a V6 SOHC. I was reading around on the site and read about removing one of the vaccum lines while idleing and seeing if there was suction and there was which I read is not good. What are the next steps for this? As I stated I just replaced the DPFE sensor so I hope it's not that. Thanks for the info though I'll be sure to check the cat when I have it up on the lift next weekend. And I just replaced my air filter when I did the DPFE sensor.

 

[XLT]

Huh. Which vacuum line did you pull? To my knowledge you should have suction even at idle.

The dpfe you just replaced probably is fine but most guys on here replace their's with the OEM motorcraft replacement. They have found them to last longer then anything else. Highly recommend.

 

[BrooklynBay]

Welcome to this forum! I've moved your thread into the stock 95-01 section.

 

[eupleili]

vacuum line

I guess the vacuum line doesn't make much sense. I think all of the posts I read yesterday were kind of running into one. I think before I mess with the cat (unless there's an easy way to check and I'm just incompitant to find it on this site) I'm going to replace the EGR valve, PCV valve, and the fuel filter, along with seafoaming the fuel tank, oil tank, and pcv line? (if that's right?). Hopefully this will kind of flush any gunk out and help the system out. And I did put the motorcraft DPFE on ... a little more money but definately worth it in the long haul (I hope!!!).

Oh', and if there's any information on the seafoam for transmissions I'd appreciate it, I'm kind of on the fence about this kind of stuff but it might be worth a shot to help out the old tranny.

Thanks Again!

 

[Joe Dirt]

Easy way to check the cat (not 100% foolproof but will give you a good idea) is to get underneath when running and use a laser temp gun to check the temp before and after the cat... Works better as the truck is warming up, and hasn't been running for a long time IMPE...

 

[eupleili]

Sorry it has been awhile. Things I have done since my last post:
1. Changed the DPFE sensor (AGAIN) ... Wasn't the Problem.
2. Changed out the Coil Pack after I found out the 2nd cylinder wasn't firing at all.
3. Changed out all of the plug wires after there was arcing in the 2nd cylinder (seems to be what killed the first coil pack)
4. Completely changed the transmission fluid and filter (What a pain)
5. Had the system ran with solvents to clean the fuel injectors.
6. Replaced the front shocks.
7. Cleaned the MAF sensor as well as the intake manifold which was covered in carbon.
After all of this, the truck is finally starting to show some promise. It is running smooth and has great power and excelleration. (Now that it is running on 6 and not 5 cylinders) My new problem shouldn't be that hard to fix, I hope. After all of my repairs my CEL was off for about 2 weeks. About a week ago, it came back on. I have noticed since that my temperature gauge is not working properly. All of my other gauges work fine but the temperature gauge goes from the very bottem to right before the first line. It never climbs any higher than that and seldom gets that high. Hoping this is causing the CEL. I had the codes pulled at autozone and they said something about the temperature being off. As I searched through the forum, I found many culprits of what this could be. Hoping someone knows a little more about this area and can steer me in the right direction. Also, If there are any questions about how I did the other repairs, just ask. Some of them were a major pain but I know how to do them now and it definately won't be as hard next time!

Thanks in advance!

 

[jremington59]

What was the code?

 

[sport97]

If your temperature gauge is not showing that the motor is warm then the thermostat is most likely stuck open. A new one is about 20 bucks. If you turn on the heat do you get any warm air? If not then you know the motor is definitely not getting warm, which rules out a faulty gauge. I believe that if your motor is cold it will cause it to run lean, which may trigger your CEL.

 

[eupleili]

The air runs fine and I don't remember the exact code, I threw out the receipt (should probably stop doing that!) Will a faulty thermostat trigger the CEL? And how big of a project is it? I like to do most things myself as long as it doesn't involve taking the motor out or something like that. Thanks for the input!

 

[yeah61794]

The thermostat is not that hard to change. Here is a great write up about it. If the engine does not warm up it will want to run rich because it will constantly keep trying to get it up to temperature by putting more fuel in.

 

[coonerboy]

That code sure would help. Kinda hard to help ya if we don't have somewhere to start.

 

[explorerguy89]

welcome to site and yes scan truck for codes for sure

 

[eupleili]

Alright guys thanks for the input I'll get the truck up to autozone this weekend and I should get the codes then!

 

[eupleili]

A little update ... I just ran the truck and realized that the heat is no where near the temperature it should be. I had it on full blast and it and only luke warm air came out. What could be causing the engine to run cold and how big of a project is it? Thanks again.

 

[yeah61794]

That definitely sounds like a thermostat stuck open to me.

 

[99SportX]

A little update ... I just ran the truck and realized that the heat is no where near the temperature it should be. I had it on full blast and it and only luke warm air came out. What could be causing the engine to run cold and how big of a project is it? Thanks again.

The solution to your problem has already been posted in this thread. T-stat is stuck open. Coolant is flowing through the engine at all times and it never gets warm. When it is running cold, it runs rich. Change the thermostat and you will be just fine.

 

[explorerguy89]

yes i agree t-stat all the way =]