When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I had a bad oil leak in the rear of the intake. Soo, pulled it apart today and the coolant hose into the TB was pinched off where it bends into the TB. Looks like someone replaced it with a regular hose.
Anyway, is it possible to re-route the hose from the left side of Tb and just slip it on (with a clamp of course) to the pipe on the passenger side? Can't tell where that pipe goes.
Also, What would happen with the ECT(engine coolant temp. sensor)? Will it throw a code if no coolant is flowing through? Fans still kick on when they're supposed to?
BTW, it's a 95.
The throttle body coolant bypass is a very common and easy mod on the LT1’s and is done just like you said. The temp sensor for the fans is actually on the water pump housing so it won’t be effected at all.
The throttle body coolant bypass is a very common and easy mod on the LT1’s and is done just like you said. The temp sensor for the fans is actually on the water pump housing so it won’t be effected at all.
Excuse my ignorance on this, but just what is this "T.B. coolant bypass mod" and what advantages are there to doing it? Thanks.
Excuse my ignorance on this, but just what is this "T.B. coolant bypass mod" and what advantages are there to doing it? Thanks.
Coolant from the upper radiator hose passes through the bottom plate on the throttle body. The intent is to warm the throttle body for cold weather operation. The gasket can leak creating issues. Especially since this is above the optispark on LT's. Don't know that it really makes much difference for performance. The process is pretty simple. You remove the hoses from the TB and join with a barbed union.
On my 92 the hoses are different sizes so I needed a barbed adapter with different size ends.
The process is pretty simple. You remove the hoses from the TB and join with a barbed union.
On my 92 the hoses are different sizes so I needed a barbed adapter with different size ends.
I'm itchin' to play with this mod. I'm not 100% certain which coolant hoses leading to and from the TB would be disconnected and joined together. I wanted to do this if I didn't have to completely remove the TB on my 1996 LT1. After removing and rejoining the coolant hoses for the bypass, do the open metal inlet and outlets on the T.B. need to be capped? Suggestions / photos / help?
Back up and running yesterday. Seems to be ok, still a little smoke after pulling back in the garage. I think it may be left over from the leak.
Retroguy...I ended up connecting the hose from the radiator directly to the pipe that runs between the intake and valve cover. It is plenty long enough.
A couple pics showing which hoses they are.
Back up and running yesterday. Seems to be ok, still a little smoke after pulling back in the garage. I think it may be left over from the leak.
Retroguy...I ended up connecting the hose from the radiator directly to the pipe that runs between the intake and valve cover. It is plenty long enough.
A couple pics showing which hoses they are.
Thank You for the pics! Did you cap the inlet and outlets to the T.B. after your mod???
I just successfully performed the "Throttle Body Coolant Bypass" this morning on my '96 LT1. I went really slow since I was working around some old plastic vacuum tubing and electrical connectors too. I did this on a cold engine. I found out the following that is needed in a stock 1996 LT1: I had to disconnect some vacuum tubing/lines to make it easier (it will be obvious what's in the way). I didn't have to remove the air intake leading to the T.B. I did have to really play with the stock "spring clip" clamps quite a bit on the coolant lines leading to and from the T.B. I used regular pliers, needle nose pliers, and even a box cutter blade to cut one of the stuck old hoses. Good news is that for a '96 LT1, I was able to reroute the original coolant line coming from the radiator on passenger side, directly to the passenger side connection near T.B. Didn't have to buy a single thing. I may leave the T.B.'s two metal ports open that used to have the coolant lines attached to them. Or I could buy some rubber caps to cover them up. Test drove it and found no leaks and runs well! Goodbye to extra heat in my Throttle Body!
DISCLAIMER: If you're driving your Corvette in winter temps under 39 degrees, you don't want to do this mod.
I have a 92 and have had mine bypassed forever. I live in Texas so don't need my throttle body winter warmed. The way I did it was to install a later model water pump that has the extra spigot on the front and piped the throttle body inlet hose directly to it.
My bad. I thought you were referring to the extra nipples on the TB. I had to tell some guy to cap it when he was wondering why the car was running bad.
IDK about the LT1 but TPIS has an IAC housing that has fewer screws and has everything else cut off.
https://www.tpis.com/parts/view/27
I bought it after my arm slipped and cut myself on the nipple I mean after the wound was dressed
My bad. I thought you were referring to the extra nipples on the TB. I had to tell some guy to cap it when he was wondering why the car was running bad.
Okay, I just wanted to make sure I wasn't missing something! Yeah, the other nipples (vacuum and fresh air supply for PCV) will definitely allow unmetered into the intake. if not connected or capped.
I have a 1985 c4 that I had to do this to see if this is where my Coolant leak into the engine was coming from. It looks like I have a blown head gasket, but... No coolant in oil, no bubbles in radiator, no rough or crazy idling but definitely white smoke in exhaust. Not even close to as much as when the hose was going through the TB.
Now it is the time to break it down and check everything else to find the coolant leak into the combustion.
Can there be a coolant leak in the intake manifold?
I have a 1985 c4 that I had to do this to see if this is where my Coolant leak into the engine was coming from. It looks like I have a blown head gasket, but... No coolant in oil, no bubbles in radiator, no rough or crazy idling but definitely white smoke in exhaust. Not even close to as much as when the hose was going through the TB.
Now it is the time to break it down and check everything else to find the coolant leak into the combustion.
Can there be a coolant leak in the intake manifold?
As much as I am in favor of doing this so you can remove the TB for regular cleaning of the IAC much easier, I am not sure that the coolant runs into the TB unless you have a crack in the TB itself. Some have removed the housing and cut it off and it doesn't look like coolant runs into the TB.
As much as I am in favor of doing this so you can remove the TB for regular cleaning of the IAC much easier, I am not sure that the coolant runs into the TB unless you have a crack in the TB itself. Some have removed the housing and cut it off and it doesn't look like coolant runs into the TB.
Are you getting coolant loss? IOW, is your coolant level dropping? If you really have a leak, the coolant has to go either into the motor where it is burned up, into the oil which turns it into milkshake or on the floor. In any case, you have to lose coolant. So besides relying on your sight, maybe you should confirm it by borrowing THIS from Autozone. You "buy" it and return it in 90 days and you get all your money back. Use the "credit" option so you don't have to have them scramble around trying to find $250 in cash.
Are you getting coolant loss? IOW, is your coolant level dropping? If you really have a leak, the coolant has to go either into the motor where it is burned up, into the oil which turns it into milkshake or on the floor. In any case, you have to lose coolant. So besides relying on your sight, maybe you should confirm it by borrowing THIS from Autozone. You "buy" it and return it in 90 days and you get all your money back. Use the "credit" option so you don't have to have them scramble around trying to find $250 in cash.
When I got the car I had to add Evens coolant to it but there was no white smoke.
The white smoke only appeared the day after a trip to the office and back about a week ago.
The person before me put Evens in the car so I had to drain that out as when it burns it is toxic to breath.
I then flushed it with water and changed the oil.
There was no milky oil, and still no milky oil with the new oil.
There was no bubbles in the radiator, and I have not run it for more than 5 mins since so I haven't noticed needing to add more water to the radiator.
I did a compression test on all cyl's and all were between 145 and 155.
But the white smoke is there, and the Evens was being burned. It is a HORRIBLE smell and taste, I do not recommend even going near that smoke to anyone if they run it and this happens to them.
I have the gasket kit down to the heads and I am getting ready to start the tear down very soon.
I will most likely send the heads out to get them checked worked on while it is apart. It just seems like the right thing to have done at this point.
10-20-2018, 06:48 PM
Throttle body coolant bypass
