05 Tacoma- #4 Cylinder Misfire, Dlr Svc "Tried Everything"

I have an '05 Tacoma, v6, Quad Cab, Long bed, no big modifications, 118k (I've owned it since it had 7 miles on it, regularly serviced, all maintenance done at the dealer).

About 2 months ago I started having a rough and rumble first-thing-in-the-morning startup that would go away after 15-45 seconds of running the engine (not happen again till the next day), and less if I put it in drive right away. I took it in when the check engine light came on and was told it was the oil valve gasket (I could be wrong with the names here, totally not a mechanic), and $500 later it was "fixed".

3 1/2 weeks later: same exact problem, exact same conditions, same everything. Take it back in to the dealer, they tell me it's #4 misfire, and after in and out of their shop for 4 weeks, finally they have "done everything", plugs, coil, wires, injection, compression, leak drip test, and a whole ton of other big truck words I don't understand. The only option now is to take off the cylinder head and send it to the machine shop to see if it's cracked.

So they tell me I either have a cracked cylinder head or cracked block, either way its cheaper to just buy another engine.

My biggest question is, anyone else had this problem? Is this even possible at 118k??

I paid blood, sweat and tears to pay off this truck, all the time with everyone telling how awesome they are and that they are indestructible trucks, lasts forever, etc.

I am not a mechanic, I'm a paramedic. I can fix a body, but not a truck.

But can anyone tell me that's baloney and to keep hunting for a shop around here that can find the real problem?

 

I have heard of a similar issue with both 4Runners and Tacomas. I believe there is information on t4r.org. Try searching for cylinder 6 misfire, that is most common. Your mileage would be about right for the issue.

 

I think you were taken to the cleaners by a bunch of stooges. Reading through your post I get this:
1. truck has momentary rough idle at cold startup
2. Some mysterious part is replaced and the problem is gone
3. 3-1/2 weeks later exact same problem is back

4. a ton of random parts are replaced which have no effect
5. now you need new engine

Is that right? Can you look through your reciepts and tell us exactly what was done the first time it went in? I can tell you that a cracked cylinder head or block does not go away after the truck warms a bit. I don't think it has anything to do with a misfire either. Most of what you paid for was wasted money.

 

Paging Chris4x4

 

On Aug 17,2012 this is what the dealership record says I paid for:

"Code P0304 #4 misfire, oil in #4 spark plug tube cel"

AD010 Gasket, Cylinder Head $23.95
AD010 Gasket, Cylinder Head $23.95
01235 Plug, Spark $6.44

Labor: $500.63

"Removed and replaced V/C gaskets and replace spark plugs, recheck OK"

I also had an oil change done at the same time, and since my differential fluid was scheduled to be done in 2k, I had that done same time as well.

Since then, other than 1 day of rental car ($25) I haven't paid a dime for the 4 trips in there. Tons of diagnostics, "no charge", which kinda set my alarms off. You get what you pay for, and I wasn't payin, so what was I gettin...

The service adviser said they changed the spark plugs, moved the coil around, compression tested, leak tested, and a blanket "everything we can do except send it to the machine shop".

Thank you everybody for your help! This is my baby (her name is Calamity Jane), and I have such high hopes for all the fun we can have in the future, but she's too sick right now to play

 

Take it somewhere else. They are trying to make bank off of you. I wouldnt pay that much. 500 for labor? GTFO

Now they say you need a new engine? When it comes down to that much $, Always get more than 1 mechanic shop to look at it.

 

OK, a missfire can be caused by a long list of items. It sounds like they have gone through that list. The problem is that most all of the usual suspects like a bad injector or coil will be permanently bad. They will not right themselves after a short warm up.

The part of the puzzle that I can't get to fit is why the VCG's fixed the problem for weeks, and then it returned. Coincidence or cause? I don't see how oil in the tube would be a cold start condition only either. Something is missing (no pun intended)

Are you getting any smoke (dark color) out the tail pipe on initial startup? Get someone to watch if you can. It may just be one puff. I'm wondering if something is momentarily fouling the #4 plug and then burning off.

Ultimately you need to find another shop to approach this from a fresh angle. We can help you collect some observations that will help.

Hopefully Chris will chime in ...........

 

Since this is the first problem *ever* (my previous car had no issues ever either) I thought at 118k, $580 to fix it was a decent deal since I'd never dropped a dime of "repair" money into her. Regular maintenance, tires, brakes, and new windshield wipers every year. Never a hiccup at all. The only thing thing I've had fixed was somebody sliced my fuel neck hose to get into my gas tank (had a locking gas cap, so that was their solution to getting my gas), and insurance paid the bill.


But this morning I picked her up from the dealership and this is what they wrote on my "detailed" description of the problem.

"Code P0304 misfire cylinder #4. Swapped #4 coil with #3 coil, misfire still present on cylinder #4. Swapped #4 injector with #1 injector, misfire still present on cylinder #4. Pressure tested cooling system, ok. Perform leak down test, ok. Recommend remove cylinder head and send to machine shop for inspection." No charge for this visit either. But the service adviser keeps saying that even if I send it to the machine shop and they find it's cracked, it would still be cheaper in the end to just get another engine put in.


As for smoke coming out on startup, I've had someone watch it two times, nothing, and I've kept an eye out the door most times as well, absolutely nothing abnormal came out. Even though I can't do much about it by myself, I still watch my fluids under the hood regularly and haven't noticed any of them being out of wack or dropping suddenly.

Anything else I can look for?

I won't be taking it back to the dealership from here on out. I've gotten some recommendations from friends of good shops around here that specialize in toyotas.

I've looked around this and other forums (including t4r.org) and this seems to be a slightly common sign of blown head gasket in these particular engines. Others who have had identical signs and symptoms as mine end up with that diagnosis. And also that toyota has even designed a whole new head gasket, and thus hinting there was a flaw in the first one to begin with.

 

My question about smoke was because I'm wondering about the head gasket too. I'm not aware of a particular problem with the head gaskets on this engine. Chris watches this stuff, so I'm looking forward to his ideas. Of course any engine can develop a leak. I think the reason this has proven elusive is because the problem is very slight. The amount of fluid required to momentarily foul a plug is very small, so your fluid level checks wouldn't necessarily catch it.

For the money you paid to have all the diagnistic work done and the new gaskets, which probably were needed, the money you paid isn't as bad as it sounded to begin with. The hell of it is, they still haven't found the problem. That's why I would get some fresh eyes on it.

My suspicion is that the problem is a leak in the head gasket at this point. Maybe someone smarter than me has a better idea . Replacing a head gasket should not cost anywhere near as much as a replacement engine. If it is a cracked head or block, boy that would be unusual given the circumstances. Let's hope that it isn't it.

 

Just saw this thread that Chloe bumped: http://www.tacomaworld.com/forum/2nd-gen-tacomas/242387-engine-code-p0304-cylinder-4-misfire.html

Looks like the head gasket was a good guess. Sounds like the tech in harshest's thread was on the ball.

Chloe, in your searches do you recall what year they changed the head gasket?

 

The parts guy at toyota said in 2010, but I'm not sure how accurate that really is. All he could say for sure is "It's a whole new design, guess we know why!"

I don't know how much you could redesign it, to my inexperienced eyes they looked the same. But then again, they were both just a picture.

In my lengthy internet travels to an attempt to educate myself, I have found multiple forums with several posts around this same issue. The cylinder #4 and/or #6 seem to misfire when the HG goes bad in '04-'07 tacoma and 4runner v6 models. But it's always the HG and its always #4 and #6 cylinders. Seems like to much of a coincidence to be accidental. But I could be wrong, no shortage of that!

 

Thanks, you're a good reasearcher! There are usually areas on the head gasket that are narrower than others, It's not uncommon for problems to replicate on a particular cylinder. Sorry it happened on yours. At least now you have a very plausible answer, and it is not a new engine. Unfortunately I have an 07, so this may be in my future as well. Best of luck.................

 

I figured that was the problem, which is why I suggested it earlier. Toyota dealerships are not familiar with it either.

 

I have an 05 Access Cab Prerunner V6 Automatic. Currently it has 149,000 miles. In October 2012, I had a regular oil service and was told that my coolant was very low and should have a coolant flush. I had it done and everything was fine for a couple of weeks. I discovered I had no heat. I went back to the service station and they told me that I had low coolant. They suggested that I had an air bubble from the coolant flush. Therefore, they did another flush and burped the system and everything was fine.

About 3 weeks later and another cold front, I tried the heat and had none. I checked under the hood and noticed that my coolant overflow reservoir was empty. I went back to the service station and they did a complete inspection. There were no leaks in the coolant system. They suggested I replace the radiator cap since I still had the original one. I tried that but after two weeks, I noticed the reservoir was empty again. I finally took it to a Toyota specialist and they ran a test and discovered exhaust in the coolant, which means a leaking head gasket.

During this time, my check engine light would come on. The first time it happened, I assumed it was the spark plugs. When I would first start my truck it would idle rough until I backed it out of the garage. It had been a few years since I had them changed, so I had them replaced. This fixed the problem for about a week, but then the check engine light returned. Now, I assumed it was the ethanol gas I had put in my truck. I tried fuel cleaner and it seemed to work. But, it would reappear after a week. I got a code and it was a misfire on cylinder 4. The next day, the check engine light was not on.

I stumbled on this thread and now I know that it is indeed the head gasket. Presently, I add coolant to my truck once a week. But, my truck has never overheated. It makes me wonder how long my truck was like this before October?? It appears that the head gasket leak does not eat up all of the coolant in the truck, or my truck would have overheated by now. Also, I am not sure why the engine light is on one day and off the next.

Instead of paying over $3500 to get the head gasket replaced, I have decided to just use that on a down payment on a new truck. I even lucked out and found a dealer her that had a 2012 Spruce Mica Double Cab 4x4 Sport with 3K miles and premium wheels for only $28,000. It looks brand new inside and out. I figured that this deal was too good to pass up so I'm trading it in. Even with the engine problems, the driver's seat itorn up (because the fabric used in the truck is not the best quality), and a couple of scratches, I am getting $7000 in trade.

I really hope the head gasket on the 2012 models will not have this same issue after 100K miles.

 

I just bought an 05 double cab tacoma with the v6 and when i test drove it the check engine light was on asked the dealership about it they didnt know anything about it and it was a sunday so service wasent there but it was a mazda dealership. We bought the extra warranty on it so anything should be covered. Bought the truck got it home took it to autozone they checked the code and it was cyl 4 misfire

so the obvious things came to mind plug, wire, coil etc. checked the car fax and low and behold right before we bought the truck about 2 weeks before they replaced the head gaskets and plugs new serpentine belt radiator flush. So tonight after almost a week of driving the check engine light is now off. But when I looked under the hood and checked the exhaust manifold header bolts, they are as rusted as a 2 dollar hooker. No way did they take them off to replace the head gaskets unless there is a way to leave the header on and pull the head off. but now the check engine light is off not sure if maybe the computer finally corrected itself or what but now im wondering what i got myself into $17000 hot mess.. any suggestions or ideas about why the check engine light would go off if it was still having an issue?

 

Maybe they forgot to clear the codes after the work was done?

 

Thread bump, but i think this may be my problem. No 4 missfire rough idle this am then everthing normal .
Go to drive home slight rough idle and check engine comes on autozone pulled a no 4 miss.

 

Very good possibility. Get a leak down test and a compression test at a reputable shop.