marosekcmo

I recently had my IACV cleaned in my 1999 Lexus ES300. The mechanic also took off the throttle body. I now have coolant coming into the throttle body and white smoke out of the tailpipe. I first thought it was a blown head gasket when I saw the white smoke. I then disconnected the bottom hose from the IACV and saw coolant leaking from it after a few minutes.

Car runs fairly fine besides the smoke which gets worse with throttle opening and a slight hesitation and roughness. Anyone have an idea to what's going on?

Thanks in advance

EEngineer

i think somehow your TB's coolant passage is leaking or somehow your mechanic connected the hoses wrong.

just by-pass the coolant going into the TB. it's there to warm up the TB for better cold starts during winter.

marosekcmo

Thanks, I've been reading about that being a problem on other cars, but nothing specific to the ES300.

Forgive my ignorance, but how do you bypass the coolant to the throttle body? Thanks for your help.

LeX2K

You shouldn't go about bypassing anything, fix it right. Either the lines were mixed up or a gasket was put in improperly, or something was not bolted down correctly. Any reason you're not taking it back to the mechanic? BTW if too much coolant is sucked into the engine it could cause damage like bent connecting rods. If it was my car I would not drive it until the leak was fixed.

Bdub215

iTrader: (1)

I second this.

That'd be hard. It takes a lot of force to blow a motor by hydrolock. believe me i hooked up some coolant hoses wrong and i locked up my motor. but new plugs and wires and a Combustion Chamber blow out later and it runs like it always did.

marosekcmo

I'll get it to the mechanic when I can. Right now, i just need it to run until the weekend and have him fix it.


So the question remains, how do I bypass the coolant lines to the TB on the ES300? I found how on just about every other lexus motor but mine. Thanks in advance. Your help is truly appreciated.

Hayk

iTrader: (1)

This is just an educated guess, but you would need to get a hose that would connect the coolant outlet with the inlet. So that the water would keep going without entering the TB. Honestly, I think your mechanic mixed up the TB hoses. There are three of them that need to be connected. Two are inlet and outlet for the coolant to flow through, and the third one is a vacuum hose. I think he connected the inlet coolant hose to where the vacuum line goes, so now you're feeding coolant to your intake manifold without recirculating it.

The hoses are molded into place and it's pretty easy to figure out which one goes where, just by looking at their shape. Go take a look and see if you can find the problem.

This is from a '97 ES300 Service Manual, but yours should be fairly similar, aside from the amount of air cleaner hoses.

marosekcmo

Thanks, that kind of helps, but my IACV has two inlets not three. Maybe the other inlet is on the left throttle body maybe since there are two TB on my car?

Hayk

iTrader: (1)

Borrowed from another thread. I see 3 hoses going to the TB's.





Use these pics as a reference and check your hoses.

marosekcmo

Man, that helps a ton. Looks like on one water bypass outlet on the left throttle boy, then the vacuum line,and secind water bypass on the right throttle body. Am i looking at that right?

So basically, detach the two water bypass hoses from the throttle body and connect them together. Then plug the inlets to the TB. Does thus sound right?

You donr know how big a help you've been. I'm limited on funds and NEED this to work until I can fix it properly. Thanks.

marosekcmo

Man, that helps a ton. Looks like on one water bypass outlet on the left throttle boy, then the vacuum line,and secind water bypass on the right throttle body. Am i looking at that right?

So basically, detach the two water bypass hoses from the throttle body and connect them together. Then plug the inlets to the TB. Does thus sound right?

You donr know how big a help you've been. I'm limited on funds and NEED this to work until I can fix it properly. Thanks.

Hayk

iTrader: (1)

No problem. Yeah just connect the coolant hoses if you want to bypass the TB. You don't really need to plug the TB holes, unless you really want to.

Before you decide to bypass the coolant flow, check that all the hoses are in the correct spots to rule out any mix ups.

marosekcmo

Quick update, I verified the two water bypass hoses and connected them. However, there still seems to be coolant in the TB. Car still smokes a little but nowhere NEAR as much which leaves me to believe the bypass worked but residual coolant is being sucked into the intake and combustion chamber.

Will the remaining coolant burn through the intake or do I need to drain the TB?

JSM

So you bypassed them or reconnected them? Sounds like you bypassed but I may have read that wrong.

If you bypassed it should eventually burn off. How far have you driven the car? I wouldn't think it would take long to burn off at all?

marosekcmo

Yes I bypassed it. ANOTHER UPDATE: There is very minimal smoke so it looks to be burning off. I haven't driven the car at all since the leak. I need to change the oil since a little coolant has gotten into it. I'll change it tonight or early tomorrow morning. I'm going to give it a test drive afterwards with my wife following me to see if there is any smoke coming out.

You guys have been a very big help. I just started a new job today that's gonna require me to travel around town quite a bit. I really needed my car to be dependable. Thank you all!!