Got a buddy with a '97, who said after washing the car and engine bay, it was running fine, but the next day started running roughly with the CEL on, and now won't run at all, just continually turns over and acts like it wants to crank about once every 4th or 5th revolution.

When scanned, it shows one of the IAT sensor codes (can't remember which one I was told now, there's like what, 4 of them?) and the P0304 Cyl. 4 Misfire code.

I haven't gotten a chance to see the car myself, just trying to help from afar. Anyone have any ideas? I figure something got wet or shorted, and this will hopefully be a simple fix.

 

Sounds like water in the coil....

 

yeah- since it happened right after the wash, I'd think that sitting it in the sun and waiting a day would dry it out. Otherwise I'd call it a coincidence with something else that happened.

 

Coil or wires.... that have gotten wet and are shorting. If you have something to swap to from a known good car, might help. You can swap your wires.... coils you should probably try drying them out.....

Unless a fuse... or something shorting elsewhere, but that doesn't seem as likely....

Dave,

 

Buddy of mine had his oil changed at an unnamed lube place. Well the tech forgot to put the filler cap back on. The result - oil all over the engine bay. He takes it back. They offer to refill. He also demands an engine wash. On the way home gets a misfire cell. Later he checked his oil again and it stinks of gasoline. So he needs another oil change.

 

Hmmm... trying to figure how that fits in here, but ok...

Anyway, so here's the deal.
I go and look the car today. He hasn't touched it for fear of screwing something up. I pulled the wires, and there was condensation on the # 4 (was worse on this one than the others, and you'll know why in a minute), 3, and 2 plug wires. I get all 4 cylinders dried out and use 4 new plug wires. Crank the car, and it runs, but there's still a hesitation/sputter to it. So I let it run for a bit to let it warm up and hopefully dry anything I couldn't/didn't get, and everything smooths out perfectly. Revs fine, idles fine, etc. So we drive it down his street, and about 20 seconds into the drive, it loses all the power, and will barely go. I shut it off and said "We're done for now." We pushed the car back up to the house, I open the hood and pull the #4 wire from the well, remembering it was a lot more wet than the others, and as I guessed, there was coolant all over and dripping off the wire, and a little on #3.
So I know it's time to replace the head gasket, but for a car that was running perfectly before the engine got washed, how in the hell did this happen?!
And I want to put something stronger than stock on there, what's a good replacement for the money for Miatas (I had a Titan gasket on my Saturn, that thing was awesome)? Also know that this car will always be a daily driver, and will probably never be modified past an intake and exhaust, if even that, it's still stock now.

 

How in the world does coolant get into the spark plug holes??

Gaskets? see Jim at Belfab

http://www.belfabracing.com/index.ph...2b01788636a0e0

 

I wish I knew about that before I ordered.

 

Sorry to resurrect the thread, but I'm about to do the work on this car and I want to make sure that I cover all the angles on it. I've not torn down a Miata yet.
Also, I'm wondering if the belfab kit is a bit overkill, don't think I need everything it has, but it is a good price.
Anyway, I plan on replacing the head gasket of course, the valve cover gasket, CAS o-ring, and the intake and exhaust gaskets. What else should I look at replacing while I'm in there?
The car is in good shape, still less than 75k, and I'm still wondering how washing the engine did this to it.
Any input is much appreciated!

 

see importperformanceparts.net I bought a head gasket and timing belt for under $50. Buy whatever other seals you might need. Maybe a waterpump as well and call it a day.

I wouldnt bother with intake and exhaust gaskets, or pull either off the head.

 

Exhaust gasket is reusable intake is not ask me how i know. Do the oil pand right reseal the oil pump with the correct gasket, and you will have alot less headache.

 

Let me resurrect this thread yet again. This past weekend, I finally was able to get to the car and pull the head off.
There was coolant pooled in cyl. 2, and oil and coolant in cyl. 4. This screams bad headgasket, but after taking it off, it looked ok. I looked all over the exposed internals, cleaned everything out, and everything else looked great.
This may sound like a dumb question, but I want to make sure everything is ok, can a bad Miata headgasket look ok? By ok, I mean no abnormalities, other than the gasket gunk was peeling off on both sides, and stringing in between the plies.

 

that is the how you see a bad HG it rarely comes from a dynamic failure of the gasket more than likely just abit of a leak. If you are concerned get the head checked. Do not reuse the HG no matter how good it looks just in case that flashed in your head

 

A step ahead of you. Gave it to a tech this morning where I work (Honda) to check it and he just got done. He said he couldn't find anything to be concerned with.
lol No, already had a new headgasket from Rosenthal waiting to go in. Just want to make sure and double-check that the problem really is that gasket. Now I'm pretty sure that it is.

 

The block can also warp but being as it is Iron and the head aluminum i doubt one would warp without the other.

 

True.
Thanks for the insight.