I bought a set of plugs from Fastlane and they are the F8DPER so I thought. Got the plugs and didn't check them against the part number. Yesterday I took great pain to install them and everything went well and truck is runing well. Today, after coming back from mall, the check engine light came on. So I check all the connections and went on to check the spark plugs, and realized the part number is F8DPP332 (also Bosch). I am wondering if the idiot light is just a coincident or that I got the wrong plugs? Are they the same, F8DPER=F8DPP332? Any suggestions? Thanks
steve

On the issue of spark plug part number.

I recently changed mine on a 99 ML 320 and the spark plugs I got from the dealer not only looked totaly different but also had a different number. I asked the dealer if they were sure they were the right plug for my vehicle and they said they were. Apparently they had been superseded by the new plugs.

Don't recall the numbers of either the old or the new plugs I put in. I've had no problems with the new plugs.

Not sure what the problem is your having. Did you us some sort of never-sieze when you put them in? If so, maybe they are not making a good ground and that's why the light went on. The connectors snap into place on each plug so make sure you got a good connection there too.

Might want to connect vehicle to an OBD-2 scanner.

Ron,
No, I didn't use any of those stuff, just a straight replacement. I got word from Phil (Fastlane) that those plugs should be fine for my application. I am thinking the MAF may be fouling up. But will get a OBDII reader to scan the code. I tried to get the Service Advisor at the dealer to scan the code for me but they urged me to make an appointment to take the truck in, so no luck. Anyhow, I disconnect the battery to make the CEL go away. Will see if it comes back.

steve

Bosch superseded the F8DPER plug to the F8DPP332 about a year ago.
Beru also supplies OE plugs for the M112/M113 engines 14FGH-8DPURX2.

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One thing that could be a problem, or so I've heard, is that you may have the plug wires on the wrong plugs. The lead on "top" of the pair of plug wires on each coil should go towards the front of the engine. Also, if you removed the MAS when replacing the plugs make sure the clamp is tight.

Gilly

Gilly and MB Doc
thanks for the comments. I plugged the wire back in the same sequence as they were taken out. As to the MAF sensor, I took a peep at it and I just could understand why it cost so much. There's just a small pcb board with a few chips soldered on it. Anyhow, the ECU is still learning the tricks after I pull the battery cable. Will see if the check engine light ever comes back.

Re: spark plugs. I just had a 99 ML 320 at a dealer and I asked about maybe changing the plugs early (before 100K miles) to hopefully avoid avoid any seizing problem (by shortening the time in service). The service manager told me there were THREE plugs per cylinder, and it was an expensive job ($500) to replace them. He said that's why they don't recommend doing it earlier than the recommendation. He said they had had no problems with seizing.

I did an "are you sure?" number on him when he said 'three plugs' and he assured me that was right. I knew there were two, but what is the story on three?

No, there are only 2 plugs per cylinder, the SA obviously doesn't know what he's talking about. Dealer charges about $12 per plug plus labor (2 hours or so). I think seizing is mainly the boot that goes onto the plug, the plugs are really easy to come off after I took the boots out. I replaced them after 6 years (53k miles) of ownership and they are dirty/corroded somewhat. If you are going to keep yours for a while, it doesn't hurt to replace them and replace them on your own to save some $$$.

There are 3 VALVES per cylinder, maybe that's where he's confused.
The recommendation in 99 was actually 100,000 miles or 4 years, so on a 99, if it were made in the fall of 98 for example, would be about due for the change. There is a month/year production date on the black label on the body side of the drivers door jamp, near the door latch striker.

Gilly