Engine problems.

[wellcraft]

Hi guiys.

I have a 1998 for explorer with the 4L SOCH engine, the other day I had to take it to advance for the check engine ligth and it came with this codes.

random / multiple cylinder misfire (po300) and also (PO171 ) system too lean (bank 1 ) and (PO174 ) system too lean (bank 2 )
It also came with (Po 304 ) cylinder 4 misfire detected and Po306 cylinder 6 mysfire detected .

My question is what could it be the problem and how it can be resolve?

Thanks in advance for any info.

 

[TheJMan]

My suggestion would be to change out all of the plugs and wires, replace the fuel filter, and run a good fuel system cleaner through the tank such as Chevron Techron or Gumout Regane.

After this is done, clear the codes by either using a scan tool or disconnecting the battery. If any of the codes come back, this should determine if there are multiple problems or if the misfire codes were triggering the system lean codes.

 

[dhoisak]

Hey Wellcraft

I had a similar problem on my 98 XLT with the 4.0L OHV engine. Starting at 98000 km and occuring every 7000km my check engine light would flash, and the engine would idle roughly. About 200 km later, the check engine light would stay on all the time. The code was a P0304, misfire on Cyl #4. Each time I would have the truck towed to the Ford dealership where I had the extended warranty that was good till 160K km.

Well everytime they would only change the #4 spark plug, do a test on the spark plug wire, and all was ok. By the 3rd time this happened, the tip of the #4 spark plug was completely melted and the plug was arcing on the piston causing th rough idle. Again the Ford dealer changed the plug and wire under warranty. Another 7000km later and now the 4th time this has happened.. I'm fuming. I told the Ford dealer to fix it once and for all. Well they changed the plugs, wires, ignition unit, but failed to properly diagnose the issue. I then went to another Ford dealership and they determined that the #4 cyl was running too rich and was getting too much fuel. They changed the fuel injector and everything was running fine for a while. Well now 12000 km later.. check engine light and rough idle and code P0304 again. Now the extended warranty is finished and I got to a private mechanic who has a race car team. He took out the motorcraft spark plugs and determined that the socket for the #4 was stripped and the plug was never seated properly in the cylinder and was burning out the plug. He re-tapped the threaded hole, nd we put Bosch platinum plugs. He checked the GEM and made some programming changed to run a bit leaner on cyl #4.. Well after all these fixes.. I now have 215,000 km on my X and I've gone some 33,000 km since the last fix without any P0304 codes and the engine still purrs nice and smooth.

Good luck

Dean