4runner still burning a little coolant- Why?

[alex.j.nassar]

Hi all,
I have a 97 4runner automatic with the 3.4 V6. Unfortunately it overheated twice earlier this year. The first time I just added water and forgot about it. The second time it overheated caused it to start burning coolant. I took it to my mechanic in August.After it was taken apart he told me that the block was slightly warped. He said that tolerance is +/- 3 thousandths and that my block was 4 thousandths off. I wasn't about the pay thousands more to have the block machined so I went ahead and had him complete the work.


1) New Head Gasket, Valve Cover Gasket, Intake Manifold Gasket, and Exhaust Manifold Gasket.
2) Machined both heads
3) New Head Bolts
4) New timing belt
5) New water pump
6) New Thermostat
7) Adjusted all valves



Ever since I got it back it runs great and gets better gas mileage than it did before. When I start it cold it blows some normal steam and then once warmed up it runs perfectly with no sign of coolant in the exhaust. For some reason I have noticed at times that when I start the motor when it is already hot it will blow a little coolant out the tailpipe. There is no coolant in the oil and I only notice any sign of this problem when the motor is started while there is pressure in the radiator. For example, I start the engine in the morning with no coolant in the exhaust (radiator not under pressure). I get on the freeway and drive 15 miles and park at work. Come back 10 minutes later and start the motor and it blows coolant out the tailpipe for a minute or so. Whereas, if I get to work and park it for 2 hours and then start it there is no coolant in the exhaust (again no pressure). I have experimented with letting the pressure out of the radiator after I park. I have noticed that if I do that it does not blow coolant ever. I have started doing this every time I stop the motor with the intention of restarting it right away but needless to say, that is annoying. What could be the problem? What would cause it to blow coolant only when the radiator is under pressure? Help please…

Thanks in advance!

 

[loko ino]

he told me that the block was slightly warped

I would think this is your issue.

why would it cost thousands to machine heads?
and if it did, you coulda went online and bought new heads.

Shortcuts never pay dividend in the end.

 

[alex.j.nassar]

I said that it would cost thousands to machine the block which would include the cost of having it removed and put back in.

 

[loko ino]

I said that it would cost thousands to machine the block which would include the cost of having it removed and put back in. READ!!!

Rude much?


Last time I'll respond to your threads.
I still stand by the reason you are leaking if the warped block.

 

[downpour11]

Rude much?


Last time I'll respond to your threads.
I still stand by the reason you are leaking if the warped block.

LOL yup that's what I thought too. Second post too! That's no way to get free advice.

 

[alex.j.nassar]

Sorry if that came across as rude guy but you responded without reading my entire post. The block was off by a hair and the machine shop and labor cost to machine the block was outrageous.

 

[scojoe]

It's burning coolant because your block is warped.....

 

[alex.j.nassar]

It might be because it is warped. I am wondering why it only blows coolant sometimes when I start the already warm engine. Also how could such a slight warpage cause a problem? It is a castiron block so how could it have warped in the first place without melting the heads and destroying the rest of the motor? I am just looking for someone that may have had a similar situation. Thanks!