Timing chain tensioner problem? | Ford Explorer Forums - Serious Explorations

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Timing chain tensioner problem?


New Member
November 20, 2010
Reaction score
City, State
Palm Bay, FL
Year, Model & Trim Level
2002 XLT
I have a 2002 4.0L Explorer. It recently had a broken timing chain tensioner on the rear timing chain.

Being out of work, and broke and all, and this being my only transpo, my friends and I pulled the engine and replaced the timing chain & gears on the back. We used the timing chain replacement tool kit & made sure everything was aligned properly, then put it back together.

Now,the engine is hard starting and kicks back. It seems to be firing early at random points (that is, sometimes it does this, not always.)

Does anybody have any ideas with regard to this? Anybody who has replaced the rear timing chain before?

Any suggestions are greatly welcome, since, as I say, I can't afford another car or to have Ford "fix" this.


sounds like you are off a tooth or 2 on the cam gear or the crank was not at TDC when the crank gears were aligned with the cams.


You said you used the timing chain replacement tool but I agree. It sounds like the cams are a little out.

Cam was out of alignment, now new problem

Good call. One of the cams WAS out of alignment, so we fixed that.

NOW it starts, runs for about 1/2 a second, floods the engine & shuts down. When you pull a spark plug, it's so wet with gas, you can see gas dripping off it, then the engine won't start again the rest of the day.

The TPS was replaced and cold air intake was installed using original mass airflow sensor, which was cleaned thoroughly with mass airflow sensor cleaner before installation.

Any thoughts on this new problem?

Thanks for any help...