Water, not Coolant, in Cylinders 4/6

My son’s 2019 Taco is at the dealer for the second time with a misfire code on Cylinder 4 and going into limp mode. I am not satisfied with the dealer’s theory on the problem.

The truck was at the dealer for the same issue 2 weeks ago. Cylinders 4/6 are getting water inside. The dealer conducted the following diagnostics:

1. compression tests-normal
2. Cooling system pressure test-passed
3. Unsure if they performed a leak down test
4. Vehicle is not overheating

Regardless, I have water in cylinders 4/6. I suspected a head gasket, cracked head, or cracked short block. However, the dealer denies any of these as possibilities.

They claim that water, but not coolant, is in cylinders 4/6—possibly caused by a missing plastic cover that goes over the coil packs on the drivers side. Supposedly there could be water running down the cowling and falling on the head, then entering through the coil and subsequently into the spark plug hole. I do not agree because there is no source of water. The truck may have been exposed to rain one time in 2 weeks, but was not on the night it threw the codes.

Any ideas before these guys clean me out from diagnostic charges?

 

What? If water could get past the spark plug, combustion would easily blast through the other direction. That makes zero sense. Only logical way for water to enter would be through condensation and even that would be almost impossible and minimal at best.

Head gasket is the most likely culprit.

I'm curious as to how they determined it was water. Taste?

 

They said it was clear rather than pink.

 

That is a whole new level of having smoke blown up your skirt.

Assuming this is not under an extended warranty, find a quality independent shop and get a proper diagnosis.

If it is under warranty, find another dealer.

 

Im with you. None of this makes logical sense. But I don’t understand why there’s no coolant in the oil and it passes compression tests.

 

So they are claiming that rain water got into your engine internals? That is one gifted diagnostic technician!

 

Update—they aren’t charging me to do the proposed repair, so I’ll let them do the work and see if the cylinders fill up again. I asked the tech to show me the cover that was missing, which he did. Still not convinced…

 

Are you sure they're saying "water inside the cylinders"?

or just water "in the spark plug tubes"?

Maybe something is getting lost in translation

 

I asked exactly this question. Inside cylinders was the response.

 

Time to find a new mechanic

 

Could you literally watch his nose grow while he was saying that?

 

X2

 

So what's the master plan?
For an impossible problem, he'll need, at the very least, an improbable fix...

 

I guess I’ll have to see if it passes all diagnostic testing after this proposed repair is complete. The same Toyota dealer “fixed” it last time and it ran fine for about 2 weeks.

TBH, I may just offload it if it runs fine again. I don’t want to be headed back to the dealer every couple weeks. I figure I could get only a couple thousand less than I paid from a dealer and just cut my losses. The good news is this is my 17 y/o son’s truck and I own it outright. He can just wait until it is either fixed or we get something else.

 

little umbrellas over the coil packs.

 

rain water getting in, is a bunch of booshit and their attempt at covering up their inability to properly diganose.
BUT, for the sake of getting it fixed, find a used plastic cover, slap it on and take it back,, or better yet try a different dealer.

GL

 

Water getting in the intake somewhere? Air filter wet?

 

It is pretty disappointing to go to the Toyota dealer and get this type of illogical theory. The only thing I could think of that supports it is if water is collecting in the spark plug housing, then dropping inside when the plug is removed. Surely they would suck the water out of the housing before removing the spark plug if this was the case. But at this point nothing would surprise me.

They insist that compression is fine and cooling system pressure test is good, even after I have asked them about the head gasket multiple times. Since they are doing this repair for free I might just trade the truck in after it is complete. If they tell me that it is good to go then they can’t argue that something is wrong with it. There’s a 2019 TRDOR with a manual transmission on the lot that’s been there a while. I might look to cut my losses to avoid several thousand dollars in a head gasket repair.

 

I never considered that, but the water is only in 4/6 cylinders. Whether this or the cowl drip theory, there is no water source. It has not rained significantly at all.