What did I buy

[jbetzelb]

Hi all, new to the site. Wish I would have joined the site before I bought. Just picked up a 98 EX sport. 100K miles. Nice and clean but according to a ford dealer in Columbia MO. it has jumped timing. I knew this when I bought and I paid a grand for the truck. It idles perfect but sputters and has no power when you try to drive it. Runs real rich. Get over about 30 mph and you would never know there is a problem. The codes are p0133 and p0156. I only question the dealer becasue I am form Omaha and know nothing about them and they spent only 20 minutes doing the diag on it. Read numerous posts on timing chains. What is the chance I only have a problem with the front timing chains and the rear is OK? Most of the forum covered the front but there and many there so I couldn't read them all.

 

[410Fortune]

so this 98 Sport is a SOHC V6 I assume?

Your codes are oxygen sensor related

133:
02 sensor circuit slow to respond, bank 1 sensor 1

156:
Downstream Heated Oxygen Sensor circuit fault - Bank No. 2.
Or O2 Sensor Bank 2 Sensor 2.

check the wiring to your 02 sensors

 

[jbetzelb]

Yes on the sohc. The exact wording from the dealer shop is

road tested. ran eec test. codes p0133 and p0156. pinpoint tested, monitored eec, power balanced. Mechanical concerns, timing chains have jumped. Recommend engine

How good would it idle if it slipped a notch in timing. The dealer told me that had no way of knowing if it was front or rear chain that failed without tearing it down. It starts as soon as you hit the starter.

 

[cross1189]

first see if you can clean the sensors then disconnect the batt. for a few minutes so the comp will reset. if the engine light comes back on time to replace the sensors with new ones. don't buy off brands they screw up easy

 

[jbetzelb]

I took it to a shop in town here and they said there was a intake leak and the cats were plugged. Sound reasonable? I had them fix the intake leak. It ran better with the intake vac leak fixed but still not good. I will take the cats off and see what that does. Are these known for plugging the cats? The exaust does sound restricted. It has new O2 sensors on it. Previous owner tried that.

 

[Cobraguy]

Bank one sensor one should be the first sensor on the right side. (not positive on that with a SOHC)

Sensor 2 bank 2 is the cat monitor on the driver's side. (again, not positive of that side on a SOHC) That is either a plugged cat or a sensor wiring problem. Rarely do those sensors go bad. But at 100K, all sensors should be replaced with genuine factory OEM sensors. There are some aftermarket sensors that are very good, but using OEM ensures you get the exact ones for your application.

What I would do is take it to a shop that can do a definitive test on your cat and see if it's plugged. There is a way to tell. Even a temp gun can tell you if you're experienced.

Take a compression check. If the compression is in specs, there is no way timing jumped. That affects compression, so you'll know. I think that shop is trying to screw you (or the used car department) out of an engine R and R. Fix the easy and obvious first before anything else.

 

[gijoecam]

I, too, highly doubt it's jumped time. if it had, there would be multiple issues with it running, and it would not even make it to 30mph. It would be sputering and backfiring all over the place, wouldn't want to run in the first place, and would be throwing codes for both sides of the engine, not just one.

My money's on another issue... I, too, would recommend a compression check. That'll verify whether or not it's a timing issue. Personally, I'd check the first cylinder on each side, and if they check-out, leave it at that.

Sounds to me like a sensor is giving an erroneous reading... TPS, MAF, and MAP sensor all come to mind. Any of them can cause the issue you've got. A good shop (or dealership) with an NGS or WDS system should be able to monitor all the sensors while it's running to determine what sensor(s) are not sending the correct signals.

-Joe

 

[Pensa]

It idles perfect but sputters and has no power when you try to drive it. Runs real rich. Get over about 30 mph and you would never know there is a problem.

I have never seen jumped timing run well at any speed. With the codes you are getting I suspect you probably have a clogged Cat.

 

[budwich]

Personally I would think that the truck would be able to compensate for a "single timing slip" to get it running... however it wouldn't be "complete compensation" and the symptoms would be running rich as everything would be "late timed".... which ultimately would do in your cat.

Further, given the "history" of an SOHC, I wouldn't rule things like that out so fast. Further, replacing a cat and continuing to run rich will like cause another replacement sooner than usual.

 

[jbetzelb]

Latest updates: The mechanic I took it to here in Omaha said it had a intake leak causing it to run rich. He thinks it was doing that for a while killing the catalyst. I have driven it a little more now. It idles perfectly smooth in park but it does it at 900 to 1000 rpm. It won't accelerate normal. If you put the pedal about three fourths to the floor it will sputter a little and then take off like mad. Originally I said get over thirty mph you would never know anything is wrong but that is not true. It doesn't have the power to pull a hill without getting into the throttle pretty good. It seems it isn't running rich since the intake leak was fixed. The exaust smells bad still but not a eye watering gas smell. I will follow the directions from the post. I can check compression easy. What is normal compression level? I can't pull the cats easy since it is welded but they sound like they have a problem. I read in a manual that you can check timing on these becasue there is a mark that lines up with part of the cam sensor. Is that true? There are two marks on the pully which jives with the manual I have. Sorry about the long post. I appreciate you all taking time on this.

 

[budwich]

On the "cat thing".... you could just "hack saw" it out (leave enough pipe on each end to put it back with "sleeves") and put in a "temporary" straight pipe fairly cheap.... that way you can continue your "testing" without forking out for a cat that might get "destroyed" again. My money is on the "slipped" timing.

PS..... normal intake leaking don't usually cause "rich running".

 

[jbetzelb]

On the "cat thing".... you could just "hack saw" it out (leave enough pipe on each end to put it back with "sleeves") and put in a "temporary" straight pipe fairly cheap.... that way you can continue your "testing" without forking out for a cat that might get "destroyed" again. My money is on the "slipped" timing.

PS..... normal intake leaking don't usually cause "rich running".

I cut them off. They were bad. Numerous loose chuncks. Still runs bad. Starting to lean toward timing. How can I prove it? FYI, busting the junk out of the catalyst, the drivers side was dark black and the passenger side was real light gray. Both cats were garabage and would have been plugging the exaust. I would say drivers side running real rich and passenger side running lean or maybe normal. Everyone please chime in. Taking all opinions. Would the rich side be the side with timing off? Is that the front chain?

 

[CDW6212R]

Yes the left head is the front timing chain. The intake leak would throw lean PCM codes, P0171/P0174. If there is/was a timing problem then there would be more obvious symptoms, noise. Any looseness of the chains would first make a bad noise, before jumping gears. It could be that someone did something with the chain, tensioners etc, before selling the truck. That might account for a bad converter yet no valvetrain noise.

I would drive it gently while doing all of the proper tune up stuff, the plugs, wires, fuel filter, clean the MAF and TB. Check the fuel pressure also, it has to be above 35psi for pre-1999 Explorers. If you can get through all of that and still have no valvetrain noise, I would then see the timing parts as a last option. But like others have discussed, unless you know that valvetrain work has been done, it's smart to do it now anyway. Regards,

 

[Cobraguy]

Personally I would think that the truck would be able to compensate for a "single timing slip" to get it running...

How? How does the ECM compensate for inaccurate valve timing? I didn't think the SOHC was a variable valve timing engine. Is it? It's not ignition timing here he's dealing with.

PS..... normal intake leaking don't usually cause "rich running".

Absolutely it can. The O2 sensor senses a lean condition because of the vacuum leak and richens that side of the engine...when in fact, it's probably only one cylinder that's affected by the vacuum leak. The other 2 on that side are now extremely rich. Since there isn't an O2 sensor for each cylinder, the ECM has no way of knowing which cylinder is lean...only which side.

This really doesn't sound like a cat problem to me. But it doesn't sound like valve timing either.

 

[CDW6212R]

Well the OBDII PCM on these does not "learn" driving habits like the later PCM's. They do a wonderful job of maintaining A/F ratios in closed loop, and can be tuned for any modifications. Hopefully some basic tune up and tests can find a better answer for him.

 

[ZBlackBeast]

Hey. I live in Omaha. I owned an SOHC and i know a decent amount about them.. mine had a slight rattle because of the timing chain.. there was a recall for it.. i dont know if you are still under the millage.. Where in Omaha do you live. Maby i could meet up with you and listen to her and see if i can tell anything different from mine.. I agree with MABY jumping time, but i dough it would run well at all... the SOHC's have NO balls under abnout 3-3500 RPM. and takes getting opened up to really show what it has considering its in such a PIG of a truck.. good luck to you!

 

[jbetzelb]

The solution: Took it to a ford dealer. They said bank 1 was off one notch in timing. Charged me $370 to tear it down, time it, check the tensioners and put it back together. They said my tensioners looked good. They said it appears someone tore it down because it looked like new head gaskets were on it and then got it off a notch in time when they put it back together. It runs good now. Seems like the price was good for the amount of work they had to do??

 

[Blacksheep Josh]

i think that sounds great. if the tensioners are good that's one less thing to worry about on the engine, cause if i'm right that's somethign to watch out for.

as long as it runs like it should.

 

[budwich]

glad you got it fixed without throwing a lot of different parts at your problem... the overall cost was actually quite reasonable. Good Luck in the future.

 

[410Fortune]

HEck yeah! good deal for that $$$$$