Ok all, here's the deal. I'm 2000 miles from home in Seattle and my ever faithful Mr. Cooper is misbehaving. Things were going really well, and I was enjoying the drive through the mountains when suddenly the CEL came on, and I noticed I was losing power. On closer observation, the car was running very rough. I pulled over and sure enough, it felt like I was running on 3 cylinders. Flashback to my Saab. I left the engine running and began disconnecting the coils one by one until I found cyl 1 (far left hand, standing in front) was not firing. I guessed this because when I disconnected the coil, it did not change the way the engine ran. All other coils nearly made the engine die.

So, I drove nearly another 200 miles in the mountains until I got to Seattle. I went to the local parts store and had them put a scanner on it, but unfortunately, it would not communicate with the ECM. So, I relied on (Saab) experience and replaced the coil. Sadly, this did nothing to improve the behavior of the motor. So, I replaced the plug, but with the same results. Since I cannot see the codes, I'm left to guessing.

I disconnected the camshaft position sensor tonight to see if that made any difference, and it did not, but I'm not sure if it should. I unplugged the battery for half an hour to see if that helped, and it did not. I tried resetting the ECU through the "secret menu", and this did nothing. The CEL is still on, and it's still running like crapola. However, kudos to the little motor because it's still pulling me around. However, I need to leave town tomorrow and it's a 2,000 mile trip back. I'd prefer to do it on 4 cylinders instead of three. What are the chances that it's the MAP sensor, or an injector? Any and all suggestions would be really appreciated.

Thanks,
Darrin

 

Map won't kick a specific cylinder, generally you'll get a pretty bad random misfire. Quick tip though when you're considering coils and a dead cylinder, move the suspected coil to another cylinder and see if the dead cylinder moves with it.

There's gotta be a shop around you that can at least pull the codes, I wouldn't suggest putting that kind of mileage on the car with a dead cylinder. If that cylinder is still getting fuel you'll wash down the cylinder walls, dilute the oil terribly and possibly burn up your cats over that range. Not to mention your ECU is going to be pulling as much fuel as possible as it will be seeing a ton of unburnt fuel at the O2's so you'll likely be leaning out the cylinders that are still working.

 

Thanks for that input. Truth be told, I am a little concerned about that kind of mileage on the dead cylinder. So, if I move the coils and the same cylinder is unresponsive, would it be safe to say that the injector is the next most likely suspect? I'll look for a shop today and see if they can give it a quick scan.

 

it is easier and faster to do a compression test on the cylinder just to be sure the mechanical parts are still alive. if the numbers are close to each other, then I would go for the injector.

when you removed cyl 1 spark plug, was it wet, dry, oily or other?

 

Yes, it would be easy to do a compression check if I were at home where my tester is. I wondered about a valve spring, etc. When I removed the plug, it was a bit oily. Not excessively, just a bit. It's an '09 with 150k on it.

 

I'm going to try to find someone who can scan the codes for me, and based upon that, I'll know what to do, hopefully. If codes still aren't attainable, I feel like the injector is next. So that's the plan. But, I'm going to do the coil switch first to see if the problem follows the coil... even though it's new.

 

mmmm...you could do the test the old fashion way...remove the plug and coil and start the car. then look at the cylinder if it's puffing air/gas out. you could also put your hand close to feel the air. at least you get an impression of what to expect.

There is also a chance if the plug is not gapped right, it will misfire. I know you replaced it, but try using a plug from another cyl.

 

So I switched the coil from cylinder 1 to cylinder 2, and cylinder 1 is still not firing. After looking to see the procedure for changing an injector is, I decided this is not something that I can do on the road. I took the car to a shop for a scan, and they were able to pull 0300, 0301, 0304, and P1497. I know the 300's are cylinder misfires, but I have no idea what the 1497 is yet because it reads as DTC-Description not found. Any clues? I'm taking it back to the shop this afternoon so they can run a full scan in hopes of identifying the problem. Any input is greatly appreciated.

 

1497 i believe is unmetered air fault code.

 

Looking at your codes and the symptoms, I'm betting my money on a burnt exhaust valve on cylinder 1. Go to a local shop and have them run a compression check on that cylinder, it's gotta have lost its compression.

I've done quite a few rebuilds now, and those who came to me with burnt exhaust valves I usually find a very bad gunk situation on the intake valves, it's that infamous carbon build-up issue. The carbon build up problem can be quite severe if you don't walnut blast your intake valves and clean up your intake path often. And those gunk can fall off the intake valve, get sucked into the combustion chamber, and stick onto the exhaust valve creating a localized hot spot and eventually burn and crack the exhaust valve.

 

Why can't you just give good news? Lol.... If that's the case, then I definitely won't be replacing that on the road. They are scanning the car right now, so we'll see what they come back with. I'll let you all know what they say. IF, in fact, it is a burnt valve, I'd appreciate thoughts on driving it back home. What can I do to prevent further damage? I'm in Seattle and headed to southern Missouri... if I could just go downhill all the way.... : )

 

Looks like you’re right... burnt valve. 😕 Is it possible to unplug the injector for this cylinder so I don’t pump unburned fuel into the cylinder and CAT?

 

You have a few options and there are pro's and con's:

1. Unplug that particular injector and drive. Doing this will save you from two things: The catalytic converter and second being that cylinder bore. If fuel gets sprayed into that chamber and no fire, you will get what's called bore wash because all the oil dressing will be washed up and you'll get a washed out bore pretty soon. That'll destroy the engine, so unplugging the fuel injector will save you from it. However, with 1 missing cylinder, and a non-functioning injector, your ECU might put it on limp mode to where your output will be further cut down and you probably can't hit high speeds on the road. So you'll just snail your car back home. What other issues may happen I don't know, but this is the cheapest option assuming no further damage be done to the engine itself. And if there are any other issues, it may come all the way down to replacing the engine, which will be quite costly in the end. If you can do the engine swap on your own, you'll probably break even with the tow truck fee, assuming you're able to source a motor quite cheap. I know for sure if you pull up to the dealership asking for them to rebuild your motor for you with new valves, they will hit you with a recommendation to replace the engine. These days they just simply won't bother to quote you a valve job because it'll economically more justifiable to replace the engine in terms of labor and cost involved.

2. Call the tow truck and ride with the driver home. This is the safest but the costliest option, but once you're back home, all you gotta do (with a sure mind) is to replace the burnt valve(s). Then you'll be back up and running without any other possible damages to deal with. (I'd probably go this route knowing how to do the rebuild job)

3. Stay where you are, go find an indy-shop who can work on rebuilding the motor with new valve., cost will probably be equivalent to towing it home. But you'll need to stick around for a few more days while in the end, you get to drive a good car back home.

4. Ditch the car, whatever it may be, you got at least a couple grand to spend on it. I'd say this is the least appealing option, but if it's not worth repairing, you can at least look at selling it locally for whatever you can get and fund the next car to go home with.

 

Thanks for all the help, guys. Issue resolved. A large deer solved the problem by running out in front of me at 70mph. Rental car on the way.

 

Oh man...hopefully the outcome is in your favor

 

I was going to say option 5: "gotten hit by an animal accidentally on the road and exercise your insured rights". LOL.

 

Re-title thread - The Deer Hunter!

 

How many tries did it take you to hit one?

 

He can't openly admit that, can he? LOL

 

Haha I wouldn't, talk about timing though.