Post Timing Chain Repair Issue (Missfires on Bank 1)

[Billy00NC]

I have a problem where the solution seems obvious but extenuating circumstances exist. Expert advice is welcome.

It started last summer. After a long trip, my 2000 Explorer XLT 4.0L SOHC engine developed the dreaded "Timing Chain Death Rattle". After a lot of research and attempts to rule out any other causes, I parked my truck and bought another SUV (sorry, but not a Ford) to drive. I had quite a bit of money in my Explorer with repairs already done, so I thought it best to hang on to it.

At tax time this year, I got a decent refund so I took my truck to a "recommended" shop. I discussed the issue with the shop owner and he seemed to be familiar with the problem. He quoted me $600-900. After a week I hadn't heard anything so my friend that recommended the shop went by to see the progress. He noted that the engine was torn down to the chains. He also thought it was unusual that the mechanic used vise-grips to hold the driver side camshaft in place. The passenger side valve cover was not removed. Two weeks later the shop informed me my truck was ready. I went to pick it up and the bill changed to $1100. The owner cranked the truck up and showed me how quiet it ran. He also showed me a picture of the front of the engine with a new front (driver's) camshaft chain & cassettes, plus a new jackshaft chain. After I paid the bill and started driving the truck home. I noticed a very rough idle (after it warmed up). But I got it home.

The next day, I cranked it up and got MIL codes P0301, P0302, P0303, (right side misfires) and P0174 (Bank 2 too lean). Imagine my surprise! I took it back to the shop, informed them of the problem, and left the truck. After a week with no contact, I called. The mechanic working on my truck said he tested it for vacuum leaks and couldn't find a problem. After another week, I drove to the shop and the owner said he had narrowed it down to a bad right side Cat. He said he would have the part in 5 days. After mulling that over on the drive home, I called and left a message for the shop to stop their work. The next day I went and got my truck. The mechanic said the owner would be back in 5 days if I needed to talk to him. Really.

I turned to the great volume of information on this forum and came across another sufferer of the one-sided misfires:

As recommended, I checked the system for vacuums and no issues there.

To rule out the Cat, I took out the bank 1 O2 sensor (upstream) to see if the engine still misfired. It did.

To rule out the O2 sensor, I swapped upstream sensors from one side to the other. At first, I still had misfire codes. I drove it a friend's to run a compression test. On the way, the PCM reported P1132 (bank 1 too lean) and P1151 (bank 2 too rich).

We had an "AHA" moment when the compression test showed cylinders 1, 2, & 3 all tested to 125 lbs and cylinders 5 & 6 (4 a little hard to get to) showed 165 and 175 lbs. With that much difference it HAS to be the right side is out of time. I think it's possible that the jackshaft which drives the right side cam was moved during the chain replacement. I'd love some input on this hypothesis.

On the way home, the truck ran even worse. The MIL codes were P1151 (bank 2 too lean) and another code (I can't remember) resembling P0156 (O2 heated sensor circuit malfunction). When I got home, I swapped both sensors back to their original locations. After running the motor, MIL codes went back to P0301-3. Please chime in on this issue as well. I checked and the 4.0 OHV has two different part numbers for left and right O2 upstream sensors, but my 4.0 SOHC uses the same part for both.

I apologize for being so detailed, but hope this will help those of you with similar experiences.

 

[rb142]

It sounds like you are spot on about the jackshaft moving and the timing being off. You are lucky it didn't slip enough to do any damage. This mechanic tried to avoid using the proper tools and got the timing wrong. Now you have to decide whether to go back and try to get him to fix his error, or decide that you don't want him hacking up your timing any more and take it to someone else (which will cost a good amount). $600-$900 is way too low for this job, so that should have been a red flag. I'm surprised he pulled the engine if only doing the front chains. (Beware that the rear chain guide could go soon too, if it hasn't already.)

I wouldn't even worry about the other codes until you have the timing fixed. There are too many variables. If you fix the timing and the other codes persist, you can look for those issues later.

 

[Tech By Trade]

Lol, Sounds like he did a half arsed job. Ask them to pull the valve covers and use the OTC kit to check the timing. No OTC kit? You went to the wrong shop.

 

[Billy00NC]

Thanks for the input and advice so far.

I did need to clarify the mechanic only tore down the front of the engine and did not remove the motor to work on it.

Additionally, I've read that if the two camshafts are 180 degrees off, the engine will run rough but run. I couldn't find anything about the effects on performance of a camshaft being a little out of time (like just one gear tooth). If that is the case, please share opinions on my symptoms matching.

I promise to keep updating this thread as my situation progresses.

The shop owner is insisting that I bring him back the truck and he will make it right. He says he is teaming up with a "Ford Master Mechanic" to solve my problem. I'm wearily taking it back.

I hate to add this, but if and when this thing passes a state inspection, I'm leaning towards selling it. I paid $2500 three years ago for it. I'm now at about that much in repairs.

 

[Billy00NC]

Well, I'm now worse off than ever...I called the next week and the owner said I should bring it back and he would stand by his warranty if the problem was his fault. I brought it back and showed him articles showing him the engine was out of time.

Two weeks later, I hadn't heard anything so I called the shop. The owner said he lost my number (it is on my original bill), but he wanted to show me something so should go back down there. I did. He had a mechanic sketch out how the LH cam was locked down so there was no way the jack shaft could move, getting the RH bank out of time. He said the RH side must have jumped a gear before I brought the truck to him the first time.

I swear the shop owner said he installed a new LH chain & cassette, and the jack shaft chain & cassette. Additionally, a friend that went to check on the first repair's progress saw two new chains near my truck ready for installation. This proves to me that this is the source of the problem. Only thing is, I think the owner is going to claim that he did not change the LH chain, therefore the jack shaft and RH cam could not have moved.

My questions...

Is it possible for the jack shaft to move with the RH cam not locked down, but the LH cam locked down?

How common is it for a RH cam chain to "jump a tooth" with it's cassette and tensioner in place?

Are there any Ford Mechanics out there that wouldn't mind making a statement (for small claims court) or could direct me to a document (say a TSB) that refers to the above questions? I don't want all my money back for the job. I just want the amount it will take to put the engine back in time.

I do want to discuss the possibility of putting the engine back in time myself, but may start another thread for that.

 

[boominXplorer]

Yes the jackshaft could be up to 20* off timing if he did the drivers bank without timing the rear bank. ALL workshop manuals say procedure is to tighten both jackshaft bolts then time right bank then left last. You must remove the top E18 E-torx bolt to the jackshaft to remove the left chain guide, no way around it (8mm bolt on left guide you can't get to).

When you loosen that E18 bolt the sprocket that goes on the front of the jackshaft has about 20* of slop. What he probably did was mark the left chain, sprocket and cam and lined it all back up and called it done. What he didn't realize is that jackshaft moved on the main sprocket when he went to reinstall and he would of never noticed if he didn't take the right valve cover off. In turn the right cam is off time and this is why you have misfires on 1,2 and 3.

Short story: He caused it

Note: As long as the rear chain guide is GOOD, you can retime the motor and it will be good to go once you do so.

 

[Billy00NC]

"Yes the jackshaft could be up to 20* off timing if he did the drivers bank without timing the rear bank. ALL workshop manuals say procedure is to tighten both jackshaft bolts then time right bank then left last. You must remove the top E18 E-torx bolt to the jackshaft to remove the left chain guide, no way around it (8mm bolt on left guide you can't get to)."

Okay...What if the shop owner claims his mechanic didn't change the LH chain, just the jack shaft chain? Could the RH chain still move? I'm asking this because his expert says my RH chain must have jumped a gear tooth before I brought him the truck.

I just have a feeling that if I sue the guy (just for the labor to re-time the engine), he'll use the one chain excuse...although I have a witness that saw the two new chains before they were installed.

 

[Tech By Trade]

If the front jackshaft gear were replaced then yes the left hand side could be out of time. Its been a while so I cant remember if you need to pull the gear to get the right hand side chain off. If he only replaced the right side chain, he still would have had to time the left side because once you move either of the gears on the jackshaft everthing is out. He would have had to set the crank to zero. Locked it so it couldn't move. Then he would have had to time the left hand cam with the otc tool, tightened the jackshaft gear on the front down. Then he could time the right side cam with the OTC tool. Also if he didn't have the OTC tool, he would have had to modify a tensioner to make the chains the right tension during timing or the timing would be out due to slack in the chains during tightening.

 

[boominXplorer]

"Yes the jackshaft could be up to 20* off timing if he did the drivers bank without timing the rear bank. ALL workshop manuals say procedure is to tighten both jackshaft bolts then time right bank then left last. You must remove the top E18 E-torx bolt to the jackshaft to remove the left chain guide, no way around it (8mm bolt on left guide you can't get to)."

Okay...What if the shop owner claims his mechanic didn't change the LH chain, just the jack shaft chain? Could the RH chain still move? I'm asking this because his expert says my RH chain must have jumped a gear tooth before I brought him the truck.

I just have a feeling that if I sue the guy (just for the labor to re-time the engine), he'll use the one chain excuse...although I have a witness that saw the two new chains before they were installed.

It's all about if he loosened the top E18 bolt holding the Jackshaft gear. You can swap the main chain by sliding the gear off the crank but he still could of touched the bolt.

On a side note anyone with the correct otc kit can time this motor start to finish in your situation in about 4 hours. You don't have to take anything off the front, just the valve covers.