is my 91 an interference engine?

[dillon1340]

is the 4.0 in my explorer an interference engine?

 

[boggs1227]

interference ?

 

[POS Camaro]

When the timing belt or chain breaks, the pistons hit the valves.

I don't know about the Ford 4.0.

 

[James909]

I believe the 4.0 OHV (which is what's in your '91) is a non-interference engine.

 

[dillon1340]

i've tried to google it but was unlucky. anywhere i can find out for sure?

 

[Maniak]

The 1991-1994 are non interference (use 90tm or 93tm head castings). I can't comment 100% for sure on the newer ones (diff piston/head configuration)..

~Mark

 

[dillon1340]

awesome. i think i will postpone my plans to change the timing set then.

 

[EMG7895]

usually the timing chain is good for the life of the motor, under normal circumstances theres no reason to mess with it.

 

[mechjames]

it will stretch over the life of the motor, but I believe the ECU will compensate for that.

i don't think its an interference engine, actually i don't think many V shaped engines are interference. I think its just a problem on straight 4's.

 

[marragtop]

Gates has a great Timing Belt Replacement Guide on their website that you can download. It tells you what engines have belts, if they are interference or not, and the recommended replacement interval. Go to www.gates.com and click on the Timing Belts link.

 

[dillon1340]

but my engine doesn't have a timing belt. also they may not break but the explorer has nylon tensioners that i'm sure wear out. i've had v8's that were interference and when the chain broke i had to replace valves. i just had the heads off to put on new head gaskets and do not want to take them off again that's why i was thinking of replacing the chain, in case it breaks. if it's not interference i'll still replace it just not as soon as i was thinking.

 

[EMG7895]

honestly I wouldnt even touch the timing chain unless your doing a full blown rebuild, do a quick search on ohv timing chains. You wont find many issues, the much more common fix for internals is replacing the worn pushrods.

 

[Maniak]

I'd have to agree.. In the past 10+ years being on EF (wow, its been a long time) I can't remember seeing anyone that needed to change the timing set on an OHV.

I replaced/rebuilt our motor at 355k miles.. nothing in the timing chain area looked overly worn. I didn't replace the timing chain set becuase I rebuilt my spare motor which had 150k or so miles (in that range).. I didn't change the timing set on that one either as it showed very little wear.

~Mark
~Mark

 

[stifler27870]

96 xlt 4.0

was wondering if a 96 explorer 4.0 was a interference engine or not can`t seem to find it in searches. my vin letter is x.

 

[james t]

No, it is not an interferance engine. 4.0 OHV timing chain virtually lasts forever (life of engine) and if it were to break (almost unpossible) it would do no harm.

FYI it would be so stretched out it would barely run long before it broke.

 

[stifler27870]

thanks alot.:roll: