My 2000 4.0 is misfiring again. Put new plugs and wires to solve the original prob. Then 3000 miles later it started missing again. Scanner said misfire detected on #4 cyl. so I replaced the plug (couldn't see anything wrong with it) and solved the problem again. Now again at around 3000 miles it's missing again. I'm using MC double plats. Anyone have any suggestions?
Thanks, David

 

I had the same problem as did another friend of mine.

The friends truck had the heads replaced under warranty twice and it still did it. I believe the problem was hairline cracks.

Mine on the other had seems to have had a pinhole leak in the head gasket. I had it foul two plugs and I noticed it drinking a little water. So I tossed in some of that radiator stop leak crap (you know, the saw dust and sand, lol) and it stopped. Haven't fouled a plug since and haven't really used any water. Don't know if that had anything to do with it but it worked either way. Knock on wood.

 

Remove the wire connector to # 4 injector and clean it with electrical contact cleaner.Then work it on and off a few times.

 

mine does exact same thing see my ringer4x4 thread...gotta try cleaning the electrical connector...rad was half empty by dealer said couldn't any leaks/ proof of it burning coolant

 

take the spark plug out and look inside the cylinder for coolant. Also look at your tail pipe, is steam coming out? if so get some on ur hand and taste it, sweet its coolant, otherwise just condensation. However what you can also do is run the truck for a bit, turn it off, take out that plug, and then try to crank it with the plug out, should spray coolant out if there is any in there (watch out sprays 50 feet in the air)

 

I'm thinking a leaky head or intake gasket. Could be a head issue.

Get a used oil analysis done to see if any coolant is getting into the oil.

 

who does used oil analysis? interested in it...expensive?

 

Easy to do and inexpensive. I've used Blackstone Labs before and it was a simple process:

http://www.blackstone-labs.com/gas_engines.html

 

thanks just sent a request for the oil collecting kit... for sure best way to know exactly the condition of my engine

 

Yep, a UOA is a very good way to take a "peek" inside the motor without having it all apart.

You'll be looking for unusually high levels of sodium and potassium in the UOA report. Those two elements in conjunction with each other are a sure sign of coolant.

Keep is posted.

 

kit came today when i change my oil will send it off... my friend told me still doesn't elimitate the possibility of burning coolant though...just if leaks into the engine oil

 

If coolant is getting into the oil then you've got a leaky headgasket/intake gasket or cracked heads. In such case, whether the coolant is also seeping into the cylinders and getting burned is pretty much irrelevent.

 

he meant coolant is not going into the oil but is getting into the cylinder and getting burnt

 

If a Ford dealer can't find any signs of an external leak, and if your UOA shows no signs of coolant in the oil, then I think the logical conclusion has to be that the coolant is getting burned up in the cylinders. Half a radiator's worth of coolant has to be going somewhere.

Troubleshooting often involves eliminating possibilities. The UOA will help you do that (at the very least).

 

happen to know their email address? the contact us page they have doesn't work ( at least for me) wanted to see if they can test coolant as well thanks ( mine is flithy)

 

got the results back...coolant in the oil filed a bbb complaint against dealer who sold me this ranger

 

dropped off ranger today at dealership... oil analysis also says possible cylinder wear..rad was half empty when i dropped it off ( last time i dropped it off they said they couldn't find any sign of coolant loss) rad was just flushed 2 weeks ago, partly because i put dex cool in it and really wanted to get all traces of it out