1998 Ford Explorer timing chain

SCOTTBART2004

MEMBER
1998 FORD EXPLORER
6 CYL
4WD
AUTOMATIC
130,000 MILES

I have a 98 explorer that was running great but I started it one day and ran rough so I took it to a shop and they said it was timing chain and low pressure on the number 5 cylinder it runs better at higher rpm's but the weird thing is that I also have no break pressure do you think they were right or something else. I don't see any viseable vacuum lines off and haven't yet checked for spark on number 5.

5 Replies

RACEFAN966

MECHANIC
5,029 POSTS

OK if you would do a compression test on the engine. To do this you get a compression tester and then you remove all the spark plugs and unplug the coil pack. Now put the compression tester in a spark plug hole make sure it is tight and crank it over at least 3 times do this on all cylinders and write the compression down as you go. Now I need you to put a swirt of oil in the cylinders (not all at once) as you check them and not the difference in compression and get back to me with the what you find on the dry and wet test. Is this the OHV 4.0 or the SOHC 4.0 engine? Is there any ticking noise as it is running that sounds like rocker or lifter noise? Get back to me and we will go from there.

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Thursday, August 27th, 2009 AT 11:48 AM

SCOTTBART2004

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When I run it it runs rough until about 2k then smooths out, after it warms up then start to get some ticking and in gear seems like no power really no audible squeeking before this started I would get some engine squeeking but would go away quick this is a sohc engine when they said that 5 was low pressure it was when they hooked it up to the engine machine but said they would have to pull the engine for more diagnosis, don't have a way to do apressure test any other ideas? And it also runs the same when I pull the plug wire for 5

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Thursday, August 27th, 2009 AT 7:56 PM

RACEFAN966

MECHANIC
5,029 POSTS

OK I have never seen a timing chain cause 1 cylinder to drop. I am not saying that the timing isn't bad it might be but either way will not cause one cylinder to drop. Now a compression test on number 5 cylinder is very important and really should be done so we can see what it is doing and then check compression on another cylinder or 2 to compare it to. Now with that as for pulling the wire and it running the same could be compression, bad plug, bad plug wire, or bad injector. So if you like we can run a couple of tests but you will need a digital mulit meter at one point. Now first when you pull the plug wire is there spark? Have you pulled the plug and checked it? I would not pull the engine as that is not required to check out the basic things that can cause this kind of problem. You only would need to pull the engine to rebuild it. Let me know what you can and if you have a digital multi meter and we will do some tests on the plug wire and the injector.

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Friday, August 28th, 2009 AT 9:53 AM

SCOTTBART2004

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Thanks for the help so far and yes I do have a digital multi meter

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Friday, August 28th, 2009 AT 9:49 PM

RACEFAN966

MECHANIC
5,029 POSTS

Ok if you would ohm the spark plug wire and get back to me with the ohm reading and the length of the wire. Also if you would pull number 5 spark plug and see what it looks like, if needed take a pic of it and include and I will look at it for you. I also need you to ohm the injector for that number 5 cylinder. Just simply unplug the injector and ohm across the the terminals of the injector itselft. Get back to me with the informantion and we will see what that tell us.