Coolant ontop on intake manifold

[Nick90vetteguy]

SO whenever I get done driving around I notice a small pool of coolant ontop of my intake manifold just below the fuel injector rail, any ideas on what it could be? new gaskets? thermostat gasket shot? throttle body cracked?

 

[vetteoz]

Dry it off , get car hot, turn engine off
Can usually hear where it is leaking from.
Most common is front crossover on intake.

Check tightness of intake bolts; common for them to back out letting coolant leak under pressure

 

[Nick90vetteguy]

Thanks agian Dr. vetteoz

 

[Nick90vetteguy]

ummm where is that? lol sorry brother lol

 

[DiceMan]

Coolant on top of right intake manifold L98

I've got the same issue on top of the right side of coolant pooling up in two of the manifold's indentations/pockets (not sure what the tech name is for them), will dry it up and heat up the car to see where it's coming from... ;squint:

 

[Hib Halverson]

Retorque the intake manifold bolts to the figure and in the pattern given in the Service Manual then road test.

If you still see leakage there, replace the intake manifold gaskets.

 

[WRECKER88]

I had the same problem with coolant pooling on the left front of the intake manifold. When i changed the fuel injectors i found the intake manifold bolts loose. I retorqued the bolts and the leak went away.

 

[vetteoz]

When i changed the fuel injectors i found the intake manifold bolts loose. I retorqued the bolts and the leak went away.

Every original TPI engine I have worked on has at least some of the bolts backed out; generally the end ones adjacent to the coolant passages

 

[DiceMan]

Retorque the intake manifold bolts to the figure and in the pattern given in the Service Manual then road test.

If you still see leakage there, replace the intake manifold gaskets.

Thanks Hib and everyone, the leak is at positions 1, 4 and a little at 5 (according to the manual bolts 1 and 4 need to be torqued to 45 ft. lbs. while all the rest need just 35 so maybe previously someone didn't torque them down properly?). I have an OK Torx wrench set but it would not fit into the tight areas with the intake manifold tubes in the way. Tried to find a Torx T-40 L-key that would fit at least into position 4 to see if the bolt was loose, spent two hours driving around and no one has Torx L-keys locally, so I'll order a set of them just to have handy. As for access to the other bolts... looks like I'll need to remove the intake manifold tubes on each side for access to the bolts to be able to properly torque them down? Started to remove the right side intake, got all of the bolts off except the far right one which is hidden behind a coolant vacuum line and some other small hoses, stopped at that point not sure if I do remove the hoses, then the intake tubes, would I need new gaskets and sealant? Any tips or advice on this project would be appreciated... :BOW

 

[jgr91vette]

hi nick

i used to have the same problem on my vette, actually its happening again but now not that bad like to find a pool on it.. when its hot if you open ur hood you should hear leakage on the thermostat gasket...
only need to change it to solve the problem....
just be sure to hear the leakage where its coming from , or it could be from the throttle body gasket, when i changed my throttle body it used to have a small leak on that gasket, but where i live its really hot so i eliminated the coolant pass thought the throttle body!!!

hope this find to be helpful!!! good luck!!!

 

[DiceMan]

Replacing Intake Manifold Gaskets

Ran across this... pretty well done with lots of photos...

Repairing L98 Tuned Port Intake - Corvette Fever Magazine

I'm going to attempt to R&R the intake gaskets (haven't pulled an intake manifold off since my '70 Chevelle in high school), this L98 has way more stuff that needs to be removed first... so far I've managed to bend a brand new Kobalt T40 socket while screwing up a torx bolt on some rusty tube, the one with a heat shield coming off the exhaust back by cylinder 8, which connects to the intake manifold. If this is any indication of how this project is going to go... aye caramaba.

 

[Nick90vetteguy]

Thank you eveyrbody!