Coolant Leak Behind Timing Cover?

[flspectra]

New here and in need of information. I have a 99 GMC 5.7. Running great, but getting drips of coolant on the floor. Went to change oil and I'm pretty sure there was a small amount of coolant that came of first. The coolant is dripping from the bottom of the timing cover. Are there freeze plugs or something behind the cover that could be leaking? Maybe it's coming from above, but I haven't found any wet areas at or above the water pump. Any clues appreciated.

 

THANKS!

[alwcurlz]

New here and in need of information. I have a 99 GMC 5.7. Running great, but getting drips of coolant on the floor. Went to change oil and I'm pretty sure there was a small amount of coolant that came of first. The coolant is dripping from the bottom of the timing cover. Are there freeze plugs or something behind the cover that could be leaking? Maybe it's coming from above, but I haven't found any wet areas at or above the water pump. Any clues appreciated.

 

THANKS!

 

Sounds like your water pump is leaking at the shaft or from a hose if it's dripping from up front. Wash down the area with a degreaser like a purple cleaner and run the engine till it's good and warm, and then check where you see the coolant coming from. A coolant leak from up front is unlikely to be connected with a leak into your crank case. If there was a leak into your crankcase, then you have a more serious problem.

[flspectra]

New here and in need of information. I have a 99 GMC 5.7. Running great, but getting drips of coolant on the floor. Went to change oil and I'm pretty sure there was a small amount of coolant that came of first. The coolant is dripping from the bottom of the timing cover. Are there freeze plugs or something behind the cover that could be leaking? Maybe it's coming from above, but I haven't found any wet areas at or above the water pump. Any clues appreciated.

 

THANKS!

 

Sounds like your water pump is leaking at the shaft or from a hose if it's dripping from up front. Wash down the area with a degreaser like a purple cleaner and run the engine till it's good and warm, and then check where you see the coolant coming from. A coolant leak from up front is unlikely to be connected with a leak into your crank case. If there was a leak into your crankcase, then you have a more serious problem.

 

 

Thanks for a reply. I just installed a new water pump, thermostat and checked all the hoses in my first attempt to eliminate this leak. I just finished running it up to temp and all I have been able to see is a drip on the bottom of the timing cover. It is a van so visibility is poor.

[alwcurlz]

New here and in need of information. I have a 99 GMC 5.7. Running great, but getting drips of coolant on the floor. Went to change oil and I'm pretty sure there was a small amount of coolant that came of first. The coolant is dripping from the bottom of the timing cover. Are there freeze plugs or something behind the cover that could be leaking? Maybe it's coming from above, but I haven't found any wet areas at or above the water pump. Any clues appreciated.

 

THANKS!

 

Sounds like your water pump is leaking at the shaft or from a hose if it's dripping from up front. Wash down the area with a degreaser like a purple cleaner and run the engine till it's good and warm, and then check where you see the coolant coming from. A coolant leak from up front is unlikely to be connected with a leak into your crank case. If there was a leak into your crankcase, then you have a more serious problem.

 

 

Thanks for a reply. I just installed a new water pump, thermostat and checked all the hoses in my first attempt to eliminate this leak. I just finished running it up to temp and all I have been able to see is a drip on the bottom of the timing cover. It is a van so visibility is poor.

 

 

You maybe didn't get the gasket sealed well enough. I would get a mirror or find some way to examine around that pump. You don't want a coolant drip getting worse. When installing a water pump/thermostat, I use a non-hardening gasket sealant called "form a gasket" which is a black goop that won't harden and seals well when using paper gaskets and will hold it to the component/part for assembly.

[flspectra]

New here and in need of information. I have a 99 GMC 5.7. Running great, but getting drips of coolant on the floor. Went to change oil and I'm pretty sure there was a small amount of coolant that came of first. The coolant is dripping from the bottom of the timing cover. Are there freeze plugs or something behind the cover that could be leaking? Maybe it's coming from above, but I haven't found any wet areas at or above the water pump. Any clues appreciated.

 

THANKS!

 

Sounds like your water pump is leaking at the shaft or from a hose if it's dripping from up front. Wash down the area with a degreaser like a purple cleaner and run the engine till it's good and warm, and then check where you see the coolant coming from. A coolant leak from up front is unlikely to be connected with a leak into your crank case. If there was a leak into your crankcase, then you have a more serious problem.

 

 

Thanks for a reply. I just installed a new water pump, thermostat and checked all the hoses in my first attempt to eliminate this leak. I just finished running it up to temp and all I have been able to see is a drip on the bottom of the timing cover. It is a van so visibility is poor.

 

 

You maybe didn't get the gasket sealed well enough. I would get a mirror or find some way to examine around that pump. You don't want a coolant drip getting worse. When installing a water pump/thermostat, I use a non-hardening gasket sealant called "form a gasket" which is a black goop that won't harden and seals well when using paper gaskets and will hold it to the component/part for assembly.

 

 

I don't want to sound unappreciative of your suggestions, but I did use sealant. I'll do some more checks but I'm pretty certain it's not the pump or the thermostat housing. As far as coolant in the oil, I'm guessing either intake manifold gasket or ?????. Do you know if there is any freeze plugs behind the timing cover?

 

Thanks again, all ideas greatly appreciated.

Chuck

[redvett]

No there are no freeze plugs behind the timing cover, if there is a coolant leak internally you would see it in the oil.

 

New here and in need of information. I have a 99 GMC 5.7. Running great, but getting drips of coolant on the floor. Went to change oil and I'm pretty sure there was a small amount of coolant that came of first. The coolant is dripping from the bottom of the timing cover. Are there freeze plugs or something behind the cover that could be leaking? Maybe it's coming from above, but I haven't found any wet areas at or above the water pump. Any clues appreciated.

 

THANKS!

 

Sounds like your water pump is leaking at the shaft or from a hose if it's dripping from up front. Wash down the area with a degreaser like a purple cleaner and run the engine till it's good and warm, and then check where you see the coolant coming from. A coolant leak from up front is unlikely to be connected with a leak into your crank case. If there was a leak into your crankcase, then you have a more serious problem.

 

 

Thanks for a reply. I just installed a new water pump, thermostat and checked all the hoses in my first attempt to eliminate this leak. I just finished running it up to temp and all I have been able to see is a drip on the bottom of the timing cover. It is a van so visibility is poor.

 

 

You maybe didn't get the gasket sealed well enough. I would get a mirror or find some way to examine around that pump. You don't want a coolant drip getting worse. When installing a water pump/thermostat, I use a non-hardening gasket sealant called "form a gasket" which is a black goop that won't harden and seals well when using paper gaskets and will hold it to the component/part for assembly.

 

 

I don't want to sound unappreciative of your suggestions, but I did use sealant. I'll do some more checks but I'm pretty certain it's not the pump or the thermostat housing. As far as coolant in the oil, I'm guessing either intake manifold gasket or ?????. Do you know if there is any freeze plugs behind the timing cover?

 

Thanks again, all ideas greatly appreciated.

Chuck

 

[flspectra]

I think I am seeing some it in the oil. When I drained the oil last, as I started to loosen the drain plug a fluid dripped on my hand after just turning the plug a 1/2 a turn or so. I was surprise because this doesn't normally happen. The fluid seemed thinner than oil and colored pinkish. When I finally removed the plug it "seemed" like a small amount of fluid thinner than oil ran out first (just tablespoons at most). There were no signs of coolant mixed in the oil (no milk shake). The vehicle hadn't run in 4-5 days. I was thinking the oil would float on any water/coolant, maybe that's what I saw.

 

Based on your info then it makes no sense that coolant could leak inside the timing cover and then drip out the bottom. So if there is water in the oil, then I guess the number one candidate is intake gaskets.

 

All good info. Appreciate input.

 

 

 

No there are no freeze plugs behind the timing cover, if there is a coolant leak internally you would see it in the oil.

 

New here and in need of information. I have a 99 GMC 5.7. Running great, but getting drips of coolant on the floor. Went to change oil and I'm pretty sure there was a small amount of coolant that came of first. The coolant is dripping from the bottom of the timing cover. Are there freeze plugs or something behind the cover that could be leaking? Maybe it's coming from above, but I haven't found any wet areas at or above the water pump. Any clues appreciated.

 

THANKS!

 

Sounds like your water pump is leaking at the shaft or from a hose if it's dripping from up front. Wash down the area with a degreaser like a purple cleaner and run the engine till it's good and warm, and then check where you see the coolant coming from. A coolant leak from up front is unlikely to be connected with a leak into your crank case. If there was a leak into your crankcase, then you have a more serious problem.

 

 

Thanks for a reply. I just installed a new water pump, thermostat and checked all the hoses in my first attempt to eliminate this leak. I just finished running it up to temp and all I have been able to see is a drip on the bottom of the timing cover. It is a van so visibility is poor.

 

 

You maybe didn't get the gasket sealed well enough. I would get a mirror or find some way to examine around that pump. You don't want a coolant drip getting worse. When installing a water pump/thermostat, I use a non-hardening gasket sealant called "form a gasket" which is a black goop that won't harden and seals well when using paper gaskets and will hold it to the component/part for assembly.

 

 

I don't want to sound unappreciative of your suggestions, but I did use sealant. I'll do some more checks but I'm pretty certain it's not the pump or the thermostat housing. As far as coolant in the oil, I'm guessing either intake manifold gasket or ?????. Do you know if there is any freeze plugs behind the timing cover?

 

Thanks again, all ideas greatly appreciated.

Chuck

 

 

 

[alwcurlz]

New here and in need of information. I have a 99 GMC 5.7. Running great, but getting drips of coolant on the floor. Went to change oil and I'm pretty sure there was a small amount of coolant that came of first. The coolant is dripping from the bottom of the timing cover. Are there freeze plugs or something behind the cover that could be leaking? Maybe it's coming from above, but I haven't found any wet areas at or above the water pump. Any clues appreciated.

 

THANKS!

 

Sounds like your water pump is leaking at the shaft or from a hose if it's dripping from up front. Wash down the area with a degreaser like a purple cleaner and run the engine till it's good and warm, and then check where you see the coolant coming from. A coolant leak from up front is unlikely to be connected with a leak into your crank case. If there was a leak into your crankcase, then you have a more serious problem.

 

 

Thanks for a reply. I just installed a new water pump, thermostat and checked all the hoses in my first attempt to eliminate this leak. I just finished running it up to temp and all I have been able to see is a drip on the bottom of the timing cover. It is a van so visibility is poor.

 

 

You maybe didn't get the gasket sealed well enough. I would get a mirror or find some way to examine around that pump. You don't want a coolant drip getting worse. When installing a water pump/thermostat, I use a non-hardening gasket sealant called "form a gasket" which is a black goop that won't harden and seals well when using paper gaskets and will hold it to the component/part for assembly.

 

 

I don't want to sound unappreciative of your suggestions, but I did use sealant. I'll do some more checks but I'm pretty certain it's not the pump or the thermostat housing. As far as coolant in the oil, I'm guessing either intake manifold gasket or ?????. Do you know if there is any freeze plugs behind the timing cover?

 

Thanks again, all ideas greatly appreciated.

Chuck

 

 

No problem. The freeze plug is on the side of the motor, driver side. I can't recall if there may be one on the passenger side as well. Coolant can be difficult to see till it gathers into a droplet, otherwise it just looks wet where it may be. If there is coolant coming off the timing cover, it has to be either the pump, hoses, or thermostat housing.

[flspectra]

New here and in need of information. I have a 99 GMC 5.7. Running great, but getting drips of coolant on the floor. Went to change oil and I'm pretty sure there was a small amount of coolant that came of first. The coolant is dripping from the bottom of the timing cover. Are there freeze plugs or something behind the cover that could be leaking? Maybe it's coming from above, but I haven't found any wet areas at or above the water pump. Any clues appreciated.

 

THANKS!

 

Sounds like your water pump is leaking at the shaft or from a hose if it's dripping from up front. Wash down the area with a degreaser like a purple cleaner and run the engine till it's good and warm, and then check where you see the coolant coming from. A coolant leak from up front is unlikely to be connected with a leak into your crank case. If there was a leak into your crankcase, then you have a more serious problem.

 

 

Thanks for a reply. I just installed a new water pump, thermostat and checked all the hoses in my first attempt to eliminate this leak. I just finished running it up to temp and all I have been able to see is a drip on the bottom of the timing cover. It is a van so visibility is poor.

 

 

You maybe didn't get the gasket sealed well enough. I would get a mirror or find some way to examine around that pump. You don't want a coolant drip getting worse. When installing a water pump/thermostat, I use a non-hardening gasket sealant called "form a gasket" which is a black goop that won't harden and seals well when using paper gaskets and will hold it to the component/part for assembly.

 

 

I don't want to sound unappreciative of your suggestions, but I did use sealant. I'll do some more checks but I'm pretty certain it's not the pump or the thermostat housing. As far as coolant in the oil, I'm guessing either intake manifold gasket or ?????. Do you know if there is any freeze plugs behind the timing cover?

 

Thanks again, all ideas greatly appreciated.

Chuck

 

 

No problem. The freeze plug is on the side of the motor, driver side. I can't recall if there may be one on the passenger side as well. Coolant can be difficult to see till it gathers into a droplet, otherwise it just looks wet where it may be. If there is coolant coming off the timing cover, it has to be either the pump, hoses, or thermostat housing.

 

 

I can see the freeze plugs clearly, they are not the source. Sounds like I will have to start uncovering the front of the engine (air box, shroud, etc) and take a good look around.

[alwcurlz]

New here and in need of information. I have a 99 GMC 5.7. Running great, but getting drips of coolant on the floor. Went to change oil and I'm pretty sure there was a small amount of coolant that came of first. The coolant is dripping from the bottom of the timing cover. Are there freeze plugs or something behind the cover that could be leaking? Maybe it's coming from above, but I haven't found any wet areas at or above the water pump. Any clues appreciated.

 

THANKS!

 

Sounds like your water pump is leaking at the shaft or from a hose if it's dripping from up front. Wash down the area with a degreaser like a purple cleaner and run the engine till it's good and warm, and then check where you see the coolant coming from. A coolant leak from up front is unlikely to be connected with a leak into your crank case. If there was a leak into your crankcase, then you have a more serious problem.

 

 

Thanks for a reply. I just installed a new water pump, thermostat and checked all the hoses in my first attempt to eliminate this leak. I just finished running it up to temp and all I have been able to see is a drip on the bottom of the timing cover. It is a van so visibility is poor.

 

 

You maybe didn't get the gasket sealed well enough. I would get a mirror or find some way to examine around that pump. You don't want a coolant drip getting worse. When installing a water pump/thermostat, I use a non-hardening gasket sealant called "form a gasket" which is a black goop that won't harden and seals well when using paper gaskets and will hold it to the component/part for assembly.

 

 

I don't want to sound unappreciative of your suggestions, but I did use sealant. I'll do some more checks but I'm pretty certain it's not the pump or the thermostat housing. As far as coolant in the oil, I'm guessing either intake manifold gasket or ?????. Do you know if there is any freeze plugs behind the timing cover?

 

Thanks again, all ideas greatly appreciated.

Chuck

 

 

No problem. The freeze plug is on the side of the motor, driver side. I can't recall if there may be one on the passenger side as well. Coolant can be difficult to see till it gathers into a droplet, otherwise it just looks wet where it may be. If there is coolant coming off the timing cover, it has to be either the pump, hoses, or thermostat housing.

 

 

I can see the freeze plugs clearly, they are not the source. Sounds like I will have to start uncovering the front of the engine (air box, shroud, etc) and take a good look around.

 

 

Also use a white paper towel to dab any areas that look shiny and see if the color is the same as your coolant which could be green if typical coolant or, orange/red which is Dex-Cool.

 

Personal Tip: If you have Dex-Cool, flush that out and put in the normal green stuff. Too many bad stories about Dex-Cool.

[flspectra]

I think I have found the source of my water leak. Intake manifold gasket. Got it out today and the area around both water passages (front of heads) is nearly disintegrated, all that's really left is the silicon bead flopping around. That area of the gasket looks like wet newspaper.

 

So I'm getting a gasket set but I'm thinking about not touching the upper gasket. I don't think I have any issue with the upper gasket so why risk making one? Good or bad decision?

 

Thanks

[alwcurlz]

I think I have found the source of my water leak. Intake manifold gasket. Got it out today and the area around both water passages (front of heads) is nearly disintegrated, all that's really left is the silicon bead flopping around. That area of the gasket looks like wet newspaper.

 

So I'm getting a gasket set but I'm thinking about not touching the upper gasket. I don't think I have any issue with the upper gasket so why risk making one? Good or bad decision?

 

Thanks

 

If you're taking it apart that far and can replace it, REPLACE IT

[flspectra]

Are than any risks going into the upper gasket area? There's got to be fuel lines, injectors, electrical wiring and whatever. Never been inside one of those. Is it risky or straight forward?

[alwcurlz]

Are than any risks going into the upper gasket area? There's got to be fuel lines, injectors, electrical wiring and whatever. Never been inside one of those. Is it risky or straight forward?

 

Oh, well in that case, if it isn't something that will come apart when you replace that gasket, then I'd leave it. Sorry, thought maybe you were taking it further apart.

[flspectra]

Well it's all back together and running. Only time will tell now how successful it was.

 

I did have a surprise at start up. Cranked right up but after a short time it started to get pretty warm (~220°) fast. I shut it down, let it cool. The rad and coolant still felt cool never got warm. When I went to restart it was hard to start and ran like it was flooded. Finally cleared out, refilled the rad (only took a small amount) and all seems fine now. I heard of "air bubbles", maybe??? I'll drive it to work the rest of the week to build some confidence before a road trip.

 

Thanks for info, much appreciated.

Chuck