I just rebuild a 4.2 V6 that blew a intake gasket and the coolant mixed with the oil and seized up and bent a rod at the same time. Now it runs great idles good 800 rpm no vibration but when the motor you push the gas alittle at 1100-1200 it shakes alittle then when you get it to 1500 and up it does not shake at all and power wise it is good and a compresion check was done to it also. Now some people that I ask say that it can be the toruqe converter, fan clutch or spark something small if anyone here can help me thanks

Carlos

 

When you rebuilt it, what parts did you replace and what did you reuse? Does it have new plugs and wires?

 

Thanks for the reply on this I used the block all the pistons but one is replaced with a new rod, new rings, reconditioned crank and camshaft , used the same pushrods and lifters, but note that everything was check to make sure they are ok by the book. I used the same balance shaft, timming chain new, and I made sure the two points matched , new oil pump, all bearings all new. Now I used also the same injectors and I send them ok to be cleaned, new plugs and wire, used the old coil pack, and new fuel filter and pump that it was a pain to get to in the tank. I have told you everything I used now the only thing is the torque converter is used from a transmission shop.

Here I will tell you history of this truck I brought this truck 1999 Ford F150 XLT extened cab all power for $1000 but the engine is sezied and then I got it to fix it up for a work truck I own a Ford F150 supercrew 03 it is nice but I do not want to trash it up so I got this for that reason. The truck sat for about 2 years it has 182,000 miles on the motor the guy who sold it to me said it has new tires brakes and tranny was rebuild before the motor went. I do not know if this problem was from before the motor went thats why I asked and I never owned a V6 4.2 so I do not know how they run or act. Thanks again for the help hear from you soon.

Carlos

 

Did you do anything with the heads?

 

Yes the only thing is change the valve stem seals and thats all I did to it and check the springs and made sure that the valve face is clean. Thanks

 

Did you check the intake ports and the backside of the intake valves for carbon deposits?

 

Yes I removed each valve one by one check and clean any build up they had and also the intake was clean out also the was nice and clean it looked like I polished them the ports

 

You can test the clutch fan and other engine-driven accessories by removing the serpentine belt. Don't drive it long with the belt off.

 

No I have not but I will try it for a few second after and check it someone from work told me that the own a Ford Aerostar the had a problem close to what I have and it was the fan clutch that was stuck. Now do you think is can be the torque converter that is off balance ?? and let me know what other things I should try??

Thanks for the help

 

Just for a update I took off the belt still no change on it but I put my hand on the intake and the motor does not shake as bad as inside the truck I had my wife gas to 1100 where it does shake and motor does not move as bad but maybe I am think the motor mounts are bad because if there was a problem it will do it all the times. Let me know if you think the same.

Thanks to all

 

I suppose that's possible - even with a balance shaft a 90 degree V6 is not fully balanced.

 

GLC do you think it can be the motor mounts have worn out?? like I said before things shake around it but not the motor it self.. Thanks for the help please if you can give me some more ideas. Thanks

 

Hey has anyone found out any info on the problem I am having with this motor or it is not a motor problem please can anyone help me with this thanks alot