2000 Tacoma Advice (Please help)

Bad spark plugs will certainly cause rough idle and running as far as fixing everything you said I would still have the valve clearance checked I think your supposed to do that every 50k miles. The exact name of the service I cant remember.

 

Judging by your first post, at the very least you need a valve adjustment. If you’re lucky that’ll fix it, but if not you probably have a burnt valve.

 

Yes thats the proper name Valve Adjustment!!

 

I'm thinking maybe our family mechanic just reset the engine light after the spark plug replacement. Possible the light doesn't turn back on until a few cycles and some drive time. I don't wanna run the risk of driving it around for a while just to see if the engine light turns back on. I'd hate to do further damage at this point.

Yeah, I think you're right. Toyota apparently ran several tests: Compression tests, leak down test and vacuum pressure tests and it seems the problem is a bad valve. So I think I'll just proceed and have a local mechanic fix it.

 

Did they show you the results of these tests and where they were out of spec and by how much? If they charged you for them, they should provide them.

I'd have it fixed, you will likely get a lot more miles out of that truck. But that Toyota estimate is WAY high.

 

This is basically what they had provided to me. In hindsight I should have posted this earlier for everyone to see haha, sorry about that.

 

No worries, thanks for posting. Just some thoughts here. They didn't elaborate on the results of the compression test or leak down test before making their recommendation, and if they really thought the valve clearances were the cause, I'm not sure why they would swap fuel injectors. I would have just followed with compression and leak down to validate a valve issue and noted that it failed.

These motors are pretty solid, and I would consider yours pretty low mileage. Personally, I'd have the local mechanic check those clearances, adjust them if possible, and redo the compression and leak down before pulling the head off. Maybe more work, but something just seems fishy to me on this. Unless it has been abused or poorly maintained, that motor is pretty young to need a bunch of head work even if you didn't have the valve clearances adjusted. Most people never do.

Anyway, it's your truck and your money. If your 2nd opinion agrees with the first, I think it's still worth having the head rebuilt and driving it for another 100K or more miles.

 

Thanks for the feedback, I really appreciate it. Looking back, I'm pretty sure I could have maintained it much better than I did. Perhaps I wouldn't have this issue if I had been more proactive about the upkeep. My expertise with vehicles is extremely novice so for the most part I don't even know what to ask for. In the past when I took it in for oil changes, I'd get recommendations and I'd just go with whatever they've said. Unless there was an engine light, oil change, or some other noticeable problem, I really didn't do much servicing on it.

This is my first and only truck I've owned since I got my license, and I'm obviously very attached to it. I'd hate to let it go, but I'm glad that there are some encouraging opinions here on this site. Thanks again! I'll keep everyone updated as I go.

 

I was an still am a novice but if you spend some time on youtube an ask questions here you can do alot more than you think you can! I have gotten to where I really enjoy working on my truck an they are actually pretty easy to work on. Mine has lived in the rust belt so thats been the hardest thing for me. Just saying if you like your truck and can put a little money here an there in some tools you will stay on top of things an have your truck for more years to come!

 

You only have 115,000 and thats awesome for a 2000! Mine is about to hit 200k an has become an awesome hobby for me. Good luck on getting it straight!

 

Yeah - I'd love to keep this thing forever if I can! And now that I've got an account here, maybe I will start to venture into educating myself a little more. Thanks for your comments!

 

Hey there! I had an almost identical issue on my truck, although at 200k miles. Don't think the valves were ever adjusted. Multiple random misfire code and cylinder #2 misfire. Checked my valves, and found all exhaust valve clearances were out of spec (tight), and the cylinder #2 was so tight I could hardly fit my smallest feeler gauge in there. I ordered shims, and installed to get them back into spec. My truck no longer misfires, although the idle is still rough. That was 15k miles ago. Might be worth doing instead of having a complete valve job if you're on a budget.

 

As others have stated, it could be as simple as a valve adjustment needed. Compression and leak down tests are useless if a valve or valves are being held open by being out of adjustment. Hope that makes sense. The dealer tech should never have continued with those tests. So first thing is to properly adjust the valves. Then you can have a compression and leak down test done. If you get good results, then you're done. And frankly, a burnt valve will generally mess with emission controls, and show up on a scanner. Don't give up hope, it may be as simple as a valve adjustment. Cheers

 

It would be unusual for the valves to be that tight at that mileage. Pull the valve cover and check the clearance yourself (or have it checked) Do you still have the old plugs?

 

This story is not adding up......its common for those valves to go 250K or more without any adjustment...
Honda's would REQUIRE 4 adjustments during that same period.....

If u truely have a valve problem at that little mileage you are very very rare here...

I would suspect a gasket leak...bad injector gasket or cup.....or even a head crack...

I would do compression test, and maybe leak gasket test with the blue dye.....

https://www.napaonline.com/en/p/BK_7001006?impressionRank=1

If you didnt care of engine very well.....that wouldnt do anything to the valves...mostly it would just use oil......
However dirty oil overheats the engine long term.......Black smoke from leaking rings and valve guides......
White smoke would be coolant getting in.......and theres lots of sources for that......

 

O'Silver_Taco -
I would agree the mileage is low for a valve issue. But a compression test will be inconclusive at this point. What will low compression show? The cylinder isn't holding pressure, right? So why is that? Your dye test will show combustion gas in the cooling system, but if that's the case you will also see bubbles in the radiator, and more likely overheating. And a compression test wont tell you if a valve is set too tight. Even if you do a leakdown test, or simply pump air into the cylinder it wont tell you if you have a valve adjusted too tight, only that air is leaking out. Got to start with checking the valve adjustment to make sure the cam isn't mechanically holding a valve open. Then proceed to a compression test, and cylinder leak down test.

 

Dont think too tight a valve is a giant killer.....if it passes those other tests...
then all that is needed is new thinner shims......$17 a piece......
no where near $5800....

If a valve is bent/burn it will fail compression test.....to tight just means....no freakin damage........new shim time....

 

Wow, sounds like yours was an easy fix. I have noticed my idle has increasingly become more rough lately. Its not horrible by any means, but compared to what I'm used to, it is noticeable. I'll let you know what I find out tomorrow, I'm having another mechanic take a look. thanks!

I have another family-friend mechanic that is going to be working on it tomorrow. I gave him a call tonight and asked him if it was possible that it may just need a valve adjustment. He seemed to be certain a valve adjustment would likely not be the fix in this instance. I'm hoping that Toyota would have at least checked the valve adjustment option first before proceeding with all these other tests and proposed fixes, but I'm not sure.

Does age have anything to do with it? Certainly if I drove it as much as others do (on average) I'd be in the 200k+ by now. Unfortunately I do not have the old plugs as they were likely tossed out by the mechanic who changed them.

After asking lots of questions and talking with all the folks here, yeah, this seems strange to me. Relatively low mileage with what appears to be a higher mileage problem. But I admittedly don't know jack about this stuff. I think Toyota ran a bunch of tests, including the compression and leak down and apparently came up with this recommendation based on all the tests they did. My Tacoma has never had any black smoke or white smoke and has never overheated once in its lifetime.
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Thanks again everyone, I appreciate all the feedback I can get! I have a mechanic working on it tomorrow, so hopefully I'll have some more information to share soon.

 

I will warn you about cracks between valves.....those leaks are weird and intermittent...
sometimes only happens under right conditions.....
But very rare to have this happen to two cylinders at once....you'd be first I heard of......

 

I would just keep driving it and see if the check engine light comes on again. The new plugs probably fixed your misfire condition. The valve adjustment is likely a different issue.