Bad valves suspected

Morning Folks , Bought my first Tacoma a month ago . Its a 1999 SR5 4x4 with the 2.7 automatic with 270,000 on it . Upon trying to troubleshoot the engine misses and trouble codes , I bit the bullet and did the compression check . Sure enough problems . I'm not sure my tester was working properly ,but worked well enough to know #1 has the biggest problem . Needle barely came up at all ,then right back down . wet or dry didn't matter . The other three came up to 150 to 160 , wet or dry didn't matter , then went right back down .
I then did a leak down on #1 with straight shop air and heard the air escaping through the exhaust . At this point , I don't know if I should start looking for another engine or pull this apart to see what I may find . My thought is , Cant put a new head on a block with 270,000 . Might be the cams or the valves , any suggestions ??? Thanks Little DAB

 

Pull the head, clean and inspect. Verify that the suspect valve is leaking. If yes, take the head to a engine machine shop. http://www.crankshaftco.com/engine-repair-directory/missouri.html Have them check all the valves and their seats for damage or excessive wear. If damage or excessive wear is noticed, have them grind the all valves (intake and exhaust) and and all their seats and verify seal. Usually when one valve is bad, the others are not far behind. The shop should be able to do all this in a day.

 

Thanks so much for that list and advice, Will the machine shop be able to shim valves to spec. ? 270,000 miles will that cause problems in lower end ?
Thanks again

 

Just wondering but are you going to try and adjust the valves first before removing the head and possibly doing unnecessary work? If your truck has always missed/stumbled then chances are its been driven that way long enough to cause damage by the previous owner. If thats the case then disregard my comment lol. However if it just started doing this id adjust the vlaves first.

 

This it true. I state the more drastic solution. 043rz is correct. Adjust the valve first, then if you can't get a good compression number, continue on with what I suggested.

About the engine machine shops capability to shim the valves to spec. Yes they can.

 

Thanks You guys . Think I will trade it in , already out of Time , Money and Patients . Lol

 

well they will need to all be done since the head rework will change all the clearances. this job is not hard and even easier with the head off and just requires a feeler gage check

if it still runs ok trade it in and get something that doesn't need work would be your best option. if you start getting into this it could become a money pit if you find other problems and cant do your own mechanic work

 

I take it the guy I bought it from had been driving like this for a while . Although I like the truck and only have $4000 in it , I just bought his problems . I believe Id be better off trading it off for a truck that bonified to start with . I gave $2800 for the truck , put another $1000 in Tires , wheels , 02 sensors , wires , plugs , radial cable (which still didn't fix the horn , Airbag , cruise control problem) etc. Already in over my head .
Since it wouldn't pass emissions , I registered out of the county I live in . I have been unemployed so I'm out of money and unless someone gives me what I have in it , I will drive it this way till I trade it in . Its on St. Louis Craigslist if anyone's interested . Thanks again for your help

 

Well I bit the bullet and tore into my 1999 Tacoma . As suspected a burnt Exhaust valve on #1 cylinder. Now to order a Head Gasket Set . Then to machine shop to have head and the rest of the valves checked . Need gasket kit before machine shop so valve guide seals can be installed with the valve

 

Got my cylinder head back from the machine shop , put it back together and it purrs like a kitten . Checked my valve clearance while the head was off , was off some but went ahead and put it together . Apparently valve shims are a dealer item , and being the weekend was out of luck . Thanks you guys for the information

 

Based on my experience don't rebuild only the head, rebuild the whole engine while you have it apart, the bottom end will fail soon if you only do the head. Also, taking your parts to a good machine shop (if you see Ferrari engines and whatnot there you'll know it's good) will result in a much better engine than any rebuilt on an assembly line engine where no effort is made to keep the parts matched up.

 

First try to adjust them and if that doesn't work, then start tearing into it. Start with the small easy things then move on to the more technical stuff.