w1ntermute0

Hello, I got a CEL a few weeks ago on my 98 e320 Wagon with 160,000 miles. Got the car from the junkyard abouy 6 mo ago so unclear what maintenance was done, although I know the gas tank was replaced with a used tank. Code was P0305 Cylinder 5 misfire. Car had just been filled up with 87, so I thought maybe that was the cause, burned up half a tank, cleared the code and filled up with 91. Stayed gone for a few days but came back. I tried swapping coil pack 4 and 5 and clearing the code again. Stayed gone for a little while again, but then came back with P0302, P0305, and P0300 (Misfire on 2 & 5 & Random Misfire). At this point I changed all the plugs and wires, cleaned the MAF and cleared the code. Stayed gone for a day but all 3 codes came back. After reading more on here, I bought a mechanic's stethoscope and just listened to the injectors. Injector #5 definitely does not have the same thack-thack-thack sound that the others do. #2 sounded in family with the others. #5 sounds more like just background engine noise, not really hearing a distinct pulse.

My question is, does this mean #5 injector is definitely bad? Is there any situation where the computer would disable the injector because of other problems? Because #2 and #5 are next to each other in the firing sequence, could this explain why it was throwing #2 also, just misreading the #5 misfire? If #5 is bad, can I remove it and clean it, or should it just be replaced? I have a bottle of seafoam on the way, I'm planning on trying that first but I'm wondering what the next steps are if that doesn't fix it.

Thanks for all the advice that I've already read here!!

wm

1986CJ7

It might be the injector or the catalytic converter getting clogged. Had the same issue, misfire code and it just went worse to the point where I thought it's the TCU cutting me down to 2nd gear and limiting me to 40kmph. Soon as I swapped the cats no more issues.

Swapped cats, booted the computer and always filled tank with 91 or 94. Stay away from 87

003stars

Hi, Can you check the injector with DVOM how much resistance on each injector do they show OHM, like 14,5 ohm etc? Probably, you will find a problem. Good luck. 003stars

w1ntermute0

Thanks - I checked 4 out of 6 injectors with the meter, with the following results:

#1 - 14.8 #4 - 14.7
#2 - 14.8 #5 - 14.9

3 & 6 were kind of hard to get to so I skipped them. I also was under the hood replacing the fuel rail supply hose. When I put the new one on, after I connected the fuel rail end I poured some seafoam directly into the hose. After completing the work, I started the engine and the #5 injector sounded good, like the others with the stethoscope. I took the car on a 10 minute drive to the store and back after clearing the code and it seemed okay. I just took it for another drive and about 20 seconds after starting the car I got the CEL. The only code it threw was #5 misfire.

When the tank gets a little more empty, I'm still going to run the rest of the seafoam through the engine, but at this point I'm thinking it's either a flaky #5 injector, or some computer gremlin that causes the signal to the injector to get disabled. Any ideas?

Thanks!!
wm

w1ntermute0

Just to answer my own question here in case anyone else has this problem: Took the car to my local mechanic, a guy I trust. He swapped injectors and problem did not move. His thought was that the head gasket was leaking slightly and letting coolant into the cylinder causing misfire. The car does use coolant slowly. He advised against trying to change the head gasket because it would cost more than the car was worth, but suggested I get two bottles of Bar's Leak 1111 head gasket. I was pretty skeptical but I said what the hell and spent the $40. He poured both right into the upper radiator hose so I wouldn't have to wait for the engine to draw it in from the expansion tank. What do you know, he was right. The car worked fine for over a year. After that, problem came back. I put two more bottles in, bam, fixed again. For $40 a year I'm pretty happy with this fix.

wm

fabbrisd1

You can also use Bar's Leak tablets.., drop's in the expansion tank before a 20min (or more drive)... ground root, old school.. goo/experience W210 mechanic

003stars

Well, good to know but you can see this site for next time may be.
www.steelseal.com Good luck. 3stars

003stars

Well, it's nice to know and you will find out at the this site ( www.steelseal.com ) for your same problem on next time. 003stars

kajtek1

Beware that all the leak sealers also leave residue on radiator tubings, so you will loose efficiency. Not a big deal in cold climates as systems are build for extreme situations, but will bite you if you drive into hot state.