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Robertgrove, Shop Owner/Educator
Category: Car
Satisfied Customers: 3
Experience:  ASE Certified Master Tech, 25yrs Exp. Calif. State Certified Instructor
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Toyota Tacoma Misfire

Customer Question

I've got a 2000 Tacoma 4x4 with 83k miles that I try to take very good care of.

Anyway, engine light came on a month or two ago. Took it to the dealer: random misfire on all four cylinders. But, the engine was running fine so it was deemed a computer error and they cleared it and I drove away.
A few days later I noticed it was running a little rough and the power was down, then the light came on again. Took it to another dealer: random misfire on all four cylinders. They suggested to start by replacing the plugs, even though they were only ~20k old. I did and the power improved a fair amount but the engine started running rougher and more frequently (the roughness had been sporadic before).
Finally this week the engine is just not sounding right all the time, so I take it back to the dealer even though the light hasn't come on yet.
They call me and say they "think" I got some water in my engine and I "may" have "bent the connector rod (or valve) in my #4 cylinder". It'll be $360 to tear the engine apart to confirm this, then if they're right, about $1,500 to fix it and put it back together.

What's going on? What's connector rod? How does water get in my cylinder, through the air intake? I've crossed some deep water, but that was many months ago and it seemed fine after that. Could that be the reason? Anything else? I don't really have $2000 to throw at this right now (when do we?).
What questions should I ask the mechanic before he starts?
thanks [email protected]
Submitted: 13 years ago.
Category: Car
Expert:  bestservices replied 13 years ago.
You didn't mention which motor you have. 4 or six cylinder both have coil packs. I would start with ignition first. The connecting rod is the rod that runs between the piston and the crank shaft. If you sucked water in the intake and into the cylinder it would bend a rod because water does not compress well at all. The pressure would bent the rod. Again if changing the spark plugs helped the condition before i would say that your problem is in the wires or the coils. Also use quality replacement parts.(ie:NGK plugs , etc. )
Expert:  FeedMySheep replied 13 years ago.
 how high was the water?
Customer: replied 13 years ago.
The water was halfway across the wheels, so about differential height. I have been informed that the intake is directly behind the blinker, so as the truck dipped into the river, if it splashed enough, I could see that occuring. I am still a bit skeptical because the truck ran fine for many weeks after crossing the water, and had crossed the water many times before, none of which splashed water above the bumper.
The dealership is checking the wires, and I will have them check the coils. Any other suggestions on what to check before they break open the engine?
Customer: replied 13 years ago.
Sorry, it is a four cylinder, does that make a difference?
Expert:  bestservices replied 13 years ago.
No not realy. I am with you on this one. I find it very hard to believe that you have a bent rod..
Expert:  FeedMySheep replied 13 years ago.

 i do not think is the water..maybe you mentioned it to them and they take advange of it

change the mecanics/dealer and get another opinion they are taking your money - they are wolfs

but sounds like a electric problem..going through the water you got some contacts coroded...


Customer: replied 13 years ago.
Update from the service manager (no longer the phone lackey), addressed most of these issues when I talked to him yesterday.

Most of the below he did without my prompting

-Yup, did a compression test. #1 is @140 all the others are at 160psi.
-He mentioned the head gasket and thought that was unlikely because I'm not leaking any fluid anywhere.
-He pulled all my wires (coils? same thing, I don't know all the terminology) and showed them to me. He said they looked fine, weren't setting off the onboard computer, but he would bench test them and switch their positions to be sure. He didn't place much faith in the bench test....
-The truck has stalled before, but I wasn't there. My GF was driving in back from VT and she thought she ran out of gas. I thought she fried the fuel pump from being so low and flying up those hills. Neither was true, had 4gls in the tank and the pump is working fine (I think.....). We chalked that one up as a mystery as the truck returned to normal after stalling and being re-gassed. This happened in the neighborhood of the stream crossings, but separated by a few days.
-He did a 'ghetto probe' while I was there, a vice-grip marking height on a rod, to show me how the #1 cylinder was low when #4 was high (both at the top?). I follow that this is bad, but don't fully comprehend why/how/etc.
-He said he would get in there with a scope and a micrometer today to further check, don't know what that means.....
-Oh, and no, I didn't tell them about water ahead of time. I went in expecting an electrical and told them as much, which is why I was really surprised when them came back with a water caused mechanical.

Thanks guys, keep it coming!

Expert:  MASTERTEKH replied 13 years ago.




Expert:  Robertgrove replied 13 years ago.

A bent rod from water injestion is only possible if it took in water throught he intake or there is a gasket/or crack problem allowing coolant into the cyl.

When this happens the rod bends (shortening it) because liquid does not compress, so as the piston comes up and hits the water the rod gives way, a little water - a little bend, lots of water - lots of bend, you get the idea.

Although 140psi is good the others are @ 160, a bent rod will lower the compession in that cyl and could give this result (but there are other posibilities also).

My first reaction would be to aggree with the other posts that it is ignition or electrically related (like water in a connector)

It could also be fuel related like and injector problem or even bad gas (water in the tank will do it!).

From reading your second post it sounds like the dealer is knowledgable and capable. If they are using a Borescope and a micrometer to check piston height and they are saying that #1 is lower in the cyl then you may have a bent rod.

This is what you can do to make sure they are  llegitimate and you are not taken advantage of:

1. Ask the dealer if they will gaurantee the repair will solve your problem.

2. tell them that when the cyl head is removed you want to verify the piston height (cyl 1&4 will be exactly even with the top surface of the block. Have the tech show you with straight edge or micrometer to measure the height difference.

3. ask them to aggree that if the cyl height is correct they will reassemble it at no charge to you.

If they are confident in there diagnosis they should have no problem agreeing. If not then get another opinion!

 Good Luck!