New engine, dealer-installed - last minute CEL tshooting suggestions
 

The engine on my 2004 was replaced this past week (at about 97K) but I've still got the dealer's loaner. Feel fortunate to slip in under the wire, but I may yet have to do further battle to ensure they don't try to bill me for unnecessary stuff.

They had a misfire on one plug and wanted to get me for a new coil and plugs. I knew I had the coil replaced less than 20K before and called them on that. I thought the plugs had also been replaced but wasn't sure when they phoned me at work while I was involved in lots of activity, so I reluctantly gave the go ahead. Later looked at the paperwork and confirmed plugs were changed at ~80K, so I'm not going to pay for them after only 17K of use. So sleazy when they have the info right there on their computer.

Didn't hear anything about the misfire after that but then there was a CEL. They were told by whomever they consult to let the computer reset over the weekend. My main concern at this point is if the CEL is still on I'd prefer to be prepared with some troubleshooting suggestions to question them with. I do do some work on the car myself (e.g. installed a new SSV with the help of Jon316G's posts and excellent video), so I do have a basic tech understanding of the car.

So, hopefully tomorrow (Monday) I'll get the call that the CEL is off and the car is ready, but in case it isn't and anyone has had a similar scenario with an engine replacement, would love to hear what cleared the CEL ...or any troubleshooting suggestions you think relevant. I DO realize I'm being vague at this time with just mention of the CEL being on. I'll report more info as soon as I have it. Thanks for reading and for your input!

Brian

If I got a new reman engine, I would put new spark plugs in it, but that's just me. I wouldn't bother with 17k miles spark plugs. But I like to change spark plugs every 15k.

And they just want to change one coil too? I probably would have ok'd that as well, even if it only had 20k miles on them too. It's just one right? I would get new spark plug wires too. The labor is next to nothing right now since they are doing the motor so your just paying for parts most of the time. I feel it's cheap insurance to do minor tune up stuff with an engine replacement.

Let's say a couple months from now, your having misfire issues with your new motor. If you did what they recommended, you could just take it back and they would take a look at it under warranty and probably not charge you a thing. Now, they can say, we recommended plugs & coils and you didn't do them, so we have to charge you diagnosis and now get to charge you more labor since the motor has already been installed and it takes more time to change them now. One to two hours diagnosis in my area would probably pay for the plugs & coils by themselves.

But good luck whatever route you choose!

He's at 97k, not sure if he'll be ok to come back in a couple months and be under warranty :p

Though i do agree, you're basically paying for parts.

A different dealer (not the one who replaced my engine) told me my coils/plugs were suspect at 30,000 miles of use, so I replaced them along with the engine "just to be sure" along with many other things to take advantage of the no/reduced labor.

I'm told my new engine had a "running rich" CEL for the first few miles. It apparently cleared up on it's own after another dozen miles, but developed an erratic idle. After replacing the SSV and doing some sort of Mazda cleaning service which cleaned the fuel injectors and intake system, the idle problem cleared up too.

So far so good now ;)

You should have an additional warranty of 1 year or 12,000 miles after any dealer work is that right? To cover their own work?

Yes, this is a good point and was actually brought up by someone else I work with. As it turns out, I just got a call that they're road testing it, so apparently the CEL was cleared. I brought up the fact that I found the paperwork and the plugs (and wires) were replaced at the same time the coil was done, but they pointed out it was over 1 year/12K so I'm still paying for the plugs. On the upside, they did give me the coil (assuming it was in fact changed).

Glad it's running well. It will be interesting to see the performance difference with the new engine compared to what I'd been used to lately.

When I did that SSV repair myself last year it was a bit of a pain at first but gave me a sublime sense of accomplishment when I was done and it was a big relief to see the CEL that the stuck SSV was causing finally go out (so the car could then pass inspection!). Not long after I did the carbon cleaning of the engine. Combined, the two did improve performance noticeably. I figured after all that work on the SSV it would be discarded during the rebuild, but since it's only the core that was redone I'll be getting my old manifold (with SSV) back.

I guess I'll know for sure tomorrow, but I'm assuming the warranty on the engine core will only be about 3K miles--the balnce until I hit 100K.

Thanks for your input.

I got all new plugs with my Reman covered under warranty, coils were still good (I replaced them not long ago)

Usually if it's misfire code, it will clear itself if it does not happen again in 2 drive cycle. 2 driver cycle means a lot of different speed up and down for maybe 10-15 minutes of driving. sometimes less sometimes more. again it depends.

Have been meaning to post a wrap-up. New engine is great. Quick starting. Nice to have performance back to normal. Thought the warranty was going to be the remainder of my 100K, so only about 3K. Pleased to discover I at least got the basic parts warranty--1 year or 12K. Though I bought a couple parts in the process, all worked out well. A minimal expense for an otherwise major repair. Kudos to Mazda. (Only negative was the Mazda 2 hatchback loaner I drove around in for 10 days. Glad to have a vehicle during that time but didn't feel 'at home' in that car. Was glad when I could stop wearing the disguise. Beard was starting to get itchy :-) ) Thanks to all who provided feedback on this post!