Cali here....loking for some thoughts.

[cali]

New to the forum. I am so grateful for all of the post and information.

I have a 98 Expy 2WD 5.4 with 110K. Having some engine issues. Drove it about 3 days ago and started running rough. CEL came on for #4 cyl miss fire. Bought all new plug and a COP for cyl 4. Installed them. Now engine runs rough. No CEL. I have gone through and checked all connections on COP's and injectors. have new PCV valve and new elbows for the vacuum line. I have also cleaned the Mass air flow sensor.

Any ideas?

Thanks


98 Expy 2WD 5.4 110K. Daily driver.

 

[JERKDOGG]

New to the forum. I am so grateful for all of the post and information.

I have a 98 Expy 2WD 5.4 with 110K. Having some engine issues. Drove it about 3 days ago and started running rough. CEL came on for #4 cyl miss fire. Bought all new plug and a COP for cyl 4. Installed them. Now engine runs rough. No CEL. I have gone through and checked all connections on COP's and injectors. have new PCV valve and new elbows for the vacuum line. I have also cleaned the Mass air flow sensor.

Any ideas?

Thanks


98 Expy 2WD 5.4 110K. Daily driver.

WUT IT DUZ-Welcome from tha CHICAGO-LAND area!!!!!

Hope U get yer prob solved asap-check to C if U gapped yer plug right-maybe tha injector(s) are dirty-im just throwin out ideas-hopefully sum1 will chime in wit a possible lead!!!!!

 

[panda24619]

i'm in SD! wooo! a lot of us here! but... hmm... it could be another cop and/or plug. did you disconnect the battery after you did it?

 

[WHOISMOOTOO]

I 2nd that disconnect the battery and try again, make sure you didnt cross thread the plug and its just knocking around in there

 

[cali]

I have disconnected the battery. I am going to re-check all the plugs today and see what happens!

 

[panda24619]

my uncle was having a problem with his jeep when he changed his plugs and he gauged them right but he bumped them putting them in. so recheck the plug too.

 

[cali]

Update..... Just checked all plugs and coil packs again. Engine still misses. Upon start up it idles at 1100 RPM with minimal miss then 20 seconds later drops to 700 RPMs and has consistent miss. Noticed a small amount of white smoke at idle with the temp at 62 deg outside. Also has a leak on right rear which appears to be coming from the head gasket. It is only wet below the head gasket.

Has any one else had this consistent miss from a head gasket on a 5.4? I read about a TSB about the head gaskets causing an oil leak on right rear and left front of the 5.4. I am thinking of getting a gauge and doing a compression test.

Any Ideas?



98 Expy 2WD, 5.4L 110K

 

[nvycrmn]

what fluid is leaking? oil i am guessing? the missing could be another COP going bad. wont actually throw a code until it goes bad though.

 

[markanthony]

I would start with the leaking fluid. If it's oil, I would go to a compression test.
If it is water/antifreeze. Look for a leaking water hose or broken connector. If compression is good, and is a broken hose. I would go for coils and plugs. I would recommend replacing them all since u r not sure what one it is. Or just replace one coil at a time. While u r at the plug with the coil off. Replace the plugs. Make sure the gap is right and double check the torque.

If their is oil leaking from the head gasket and the compression is low in one or two cylinders that is lower then the others. I would get that fixed before I went after the coils and plugs.

Most of the time a bad gasket can do all kinds of things. Missing, backfires, blow by, blue/white/black smoke, overheating, not heating up, (air) leaks that u can hear. I have seen oil being squirted out of the head gasket. I have done compression tests and had perfect compression and had white smoke out the pipes. I have oil in the water/antifreeze and the other way around.

 

[99 Expy]

I'm not sure about your oil leak, but are you sure it is your #4 cylinder that is missing again? If one COP or plug went bad, then the rest could be on their way out too. I would recommend replacing them all, but doing a compression test would be what I would do first. It sucks that #4 is all the way in the back. I am not looking forward to getting back there to change my valve cover gasket.