rough idle and a bad ping/lifter type noise

[honyak45]

My 91' navajo is idling rough and i'm going to try the remedies mentioned here but there is also a pinging in 1st and 2nd gear when starting off.It sounds like a bad lifter noise or kind of like the timing is off and its pinging like crazy.Anyone have any ideas what this could be?I'm praying its not lifters that need replacing or a bearing somewhere because i don't want to have to tear into this motor.I just put a clutch in it without a tranny jack or anything and it was a ***** so i'm about sick of bustin knuckles right now.Could this be something easily fixed maybe?Any help would be greatly appreciated. Its got a 4.0L V-6 in it with manual tranny.I also hear a tapping like a lifter when its idling.

 

[walterd140]

Clean the air sensor (MAF). It's located between the air intake & the filther. need a torx 10 I think (star wrench). That might help.

Walter

 

[honyak45]

well i cleaned both sensors mentioned here but its still pingning a lot in 1st and 2nd it seems to be only in one spot giving it gas, just over or under that spot in rpm's it doesn't ping.I just put seafoam in my gas and oil to see if its really as helpful as people say it is so do i change my oil after i let the seafoam stay in there for a little while?I tried octane boost too but there wasn't any change.

 

[walterd140]

Thought I read something about a tranny sensor, but that might be for automatic only. I would think oil might be an issue, or the oil filther. Change them lately? Timing is per-set, so I don't think there is anything there to mess with.
You might be looking at taking the head off, sorry to say.
Walter

 

[honyak45]

I noticed that the pinging doesn't start until the truck warms up(several others here have said the opposite).I started it up this morning and drove right off before it had warmed up at all and there was no pinging or rapping until it got warm then sure enough it started right in pinging again.This is making me think that it is lifters because i'm thinking maybe once the oil is warmed up and thinner then the lifters start knocking(i would think that it would get oil easier if warm too though).I'm not a mechanic so i'm not gonna go by what i think it is.Somehow i'm going to have to get it put on a analyzer to see exactly what needs to be done to get the motor running perfectly.Both the motor and tranny are tight as hell other than that pinging and ****.I love this truck already I got the deal of my life on it!!! yeeee haaaaaaaaaa.

P.S. oh yeah i got rear ended today by a hit and run driver i was pissed he hit us HARD! then took off i was going to chase him but didn't but i got his plate the good part was that his car was demolished and my truck barely had a few scratches on it!!! ha haaaaaaaaaa!

 

[Bwana Bob]

Ping

Your pinging sounds like classic carbon buildup in the combustion chambers, especially if cleaning the MAF didn't help. I suggest you do the "suck Seafoam into the engine via a vacuum port" procedure. You can find the procedure if you do a search. The basic procedure is also printed on the Seafoam can. I use the vacuum line that connects to the charcoal canister purge solenoid. (Be careful when disconnecting this hose because the connection on the solenoid is brittle plastic).

On the lifter noise, this is common to the older 4.0L OHV engines. Delta Camshaft sells a kit to fix this, but you may have good luck just by changing the oil to a high milelage type. I use Castrol High Mileage 5W-30 and the lifters seem quieter.

Bob

 

[jimwww]

Change to 91 gas for a while and see if it makes any difference.

 

[honyak45]

Change to 91 gas for a while and see if it makes any difference.

been running 92 in it since i got it doesn't help neither did octane boost or putting seafoam in the gas and oil i'll try it through a vacuum line

 

[TedJ]

I beleive that Ford reccomends against using anything but 87. If i remember correctly the TSB said about going over 3k rpm once a drive cycle to help remove carbon build up, and to not use anything but 87 because the higher octanes will cause carbon buildup and pinging. Seafoam might be a good idea...but switch your gas first. And if you usually drive like a granny, then give it hell once or twice, might knock some carbon out.

-Ted