C3 Tech/Performance V8 Technical Info, Internal Engine, External Engine, Basic Tech and Maintenance for the C3 Corvette
Sponsored by:
Sponsored by:

Coolant Issues

Thread Tools
 
Search this Thread
 
Old Aug 30, 2014 | 09:16 PM
  #1  
fka466's Avatar
fka466
Thread Starter
Heel & Toe
 
Joined: Aug 2014
Posts: 15
Likes: 0
From: Hampton VA
Default Coolant Issues

Good Day Everyone,

Newbie here. I just finished replacing my water pump and power steering pump today. When the job was done I filled the coolant system with GM recommended fluid and took the car out for a drive. I noticed that the car seemed to run warmer than normal, but not too hot to cause me any concern. When I got home I popped the hood to look for any abnormalities. Well i noticed some coolant around the driver side inlet of the water pump. I started looking around more and saw there was a drip from the hose that ran to the intake. I figure I will just tighten that clamp down and be done with it. Well as I continued to look around, I noticed there was a large spot on the inside of the hood, coolant had sprayed all over it.

To be honest I am quite baffled. I am assuming the seal on the water pump did not take and sprung a leak. Can anyone confirm this thought?

I also noticed something else strange. When i would take the car to higher speeds for long periods of time the temperature would rise quite a bit. Any thoughts?

Thank you in advance. Here are some pics from today's cruise.



Reply
Old Aug 30, 2014 | 09:47 PM
  #2  
76CSRvette's Avatar
76CSRvette
Burning Brakes
 
Joined: May 2014
Posts: 1,094
Likes: 16
From: Los Angeles California
Default

is your fan clutch any good. Did It drip gallons or like small amount. have you driven it around and then pulled over leave car running and pop open hood to check where its coming from precisely. Also do you still have the fan shroud and if so is it installed correctly with all the seals. For the water did you make sure all gaskets were set properly and tightened. for hoses if they are old might as well replace them as they may have cracked and/or will soon.
Reply
Old Aug 30, 2014 | 09:57 PM
  #3  
fka466's Avatar
fka466
Thread Starter
Heel & Toe
 
Joined: Aug 2014
Posts: 15
Likes: 0
From: Hampton VA
Default

Originally Posted by 76CSRvette
is your fan clutch any good. Did It drip gallons or like small amount. have you driven it around and then pulled over leave car running and pop open hood to check where its coming from precisely. Also do you still have the fan shroud and if so is it installed correctly with all the seals. For the water did you make sure all gaskets were set properly and tightened. for hoses if they are old might as well replace them as they may have cracked and/or will soon.
I am probably going to replace the fan clutch. I should have done it but for whatever reason I didn't.

It looks like it was just a small amount. I did not know it happened until I got home from a good little drive around town. I did start the car when i noticed the stuff on the hood but did not see anything leaking.

The fan shroud is still in the car. I did not remove it for this job so I am assuming that is ok.

The gaskets seemed to be seated properly. I used permatex ultra black gasket maker on the motor then the physical gasket on the pump.

Hoses are brand new.

I will get a fan clutch tomorrow if I can find one. I also saw on some older threads that burping the system may do the trick. I was hoping my method of filling the radiator wouldn't allow for much air in the system. I had the front end lifted in the air. I then filled the radiator with fluid. Started the car with the cap off, then shut the car off. Added fluid. Repeat. When it wouldn't take any more fluid, I added fluid to the reservoir.
Reply
Old Aug 30, 2014 | 10:11 PM
  #4  
Mike Ward's Avatar
Mike Ward
Race Director
10 Year Member
 
Joined: Jul 2001
Posts: 15,892
Likes: 42
Default

I see nothing in your symptoms that suggests a bad fan clutch (?)

Let the car run at idle with hood open looking for the leak. It might be a bad shaft seal and the fan is blowing the leakage around. Make sure the coolant recovery tank doesn't run dry.
Reply
Old Aug 30, 2014 | 11:07 PM
  #5  
fka466's Avatar
fka466
Thread Starter
Heel & Toe
 
Joined: Aug 2014
Posts: 15
Likes: 0
From: Hampton VA
Default

Originally Posted by Mike Ward
I see nothing in your symptoms that suggests a bad fan clutch (?)

Let the car run at idle with hood open looking for the leak. It might be a bad shaft seal and the fan is blowing the leakage around. Make sure the coolant recovery tank doesn't run dry.
I don't think the fan clutch is causing a leak by any means, however I do think it may be causing some issues with the temperature rising so fast. I could be wrong.

Ok. So I just cleaned the area so I could get a better idea of whats going on. I drove the car around the city a bit. The temp never got over 200. I hit the interstate however, the temp starts to climb. When i get off the interstate, the temp never comes back down under 200. I noticed some fluid had leaked around the drive side inlet of the pump.

When i removed the old pump I took out a bolt and it had some coolant behind it. After I cleaned the area around that bolt and let it sit a while, I noticed some fluid building up around the lock washer of this bolt. Could this be the issue? I don't know what is behind that bolt...

Thank you.
Reply
Old Aug 30, 2014 | 11:14 PM
  #6  
Mike Ward's Avatar
Mike Ward
Race Director
10 Year Member
 
Joined: Jul 2001
Posts: 15,892
Likes: 42
Default

Originally Posted by fka466
I don't know what is behind that bolt...
Coolant.

Running hot on the highway is not a problem with the fan or clutch.
Reply
Old Aug 30, 2014 | 11:30 PM
  #7  
76CSRvette's Avatar
76CSRvette
Burning Brakes
 
Joined: May 2014
Posts: 1,094
Likes: 16
From: Los Angeles California
Default

https://www.corvetteforum.com/forums...lutch-bad.html
Reply
Old Aug 30, 2014 | 11:37 PM
  #8  
nivek1's Avatar
nivek1
Advanced
Supporting Lifetime Gold
10 Year Member
 
Joined: Mar 2014
Posts: 71
Likes: 1
From: Sonoma Ca
Default

I've seen many posts that have brought up air in the system will definitely cause what you're going through. Search for high temp problems and there are a couple great remedies for making sure you get ALL the air out of the system. Good luck!
Reply
Corvette Stories

The Best of Corvette for Corvette Enthusiasts

story-0

5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2

 Michael S. Palmer
story-1

2027 Corvette vs The World: Every Model vs Closest Competitor

 Joe Kucinski
story-2

10 Most Common Corvette Problems of the Last 20 Years!

 Joe Kucinski
story-3

5 MOST and 5 LEAST Popular Corvette Model Years in History!

 Joe Kucinski
story-4

2027 Corvette Buyer's Guide: Everything You Need to Know!

 Joe Kucinski
story-5

10 Things C8 Corvette Owners Hate (But Won't Tell You)

 Joe Kucinski
story-6

10 Best Corvettes Coming to Barrett-Jackson Palm Beach 2026!

 Brett Foote
story-7

Every Corvette Grand Sport Explained! (C2, C4, C6, C7, & C8)

 Joe Kucinski
story-8

Grand Sport & Grand Sport X Launch Alongside All-New 535hp LS6 V8!

 Michael S. Palmer
story-9

5 Reasons Bad Drivers Crash & 5 Ways to Avoid a Costly Mistake!

 Joe Kucinski
Old Aug 31, 2014 | 03:01 AM
  #9  
doorgunner's Avatar
doorgunner
2026 Loser of the Year
Supporting Member
10 Year Member
Veteran: Army
Photogenic
Photoriffic
 
Joined: Sep 2013
Posts: 36,497
Likes: 6,969
From: New Or-leens Loo-z-anna
Default

Originally Posted by fka466
I don't think the fan clutch is causing a leak by any means, however I do think it may be causing some issues with the temperature rising so fast. I could be wrong.

Ok. So I just cleaned the area so I could get a better idea of whats going on. I drove the car around the city a bit. The temp never got over 200. I hit the interstate however, the temp starts to climb. When i get off the interstate, the temp never comes back down under 200. I noticed some fluid had leaked around the drive side inlet of the pump.

When i removed the old pump I took out a bolt and it had some coolant behind it. After I cleaned the area around that bolt and let it sit a while, I noticed some fluid building up around the lock washer of this bolt. Could this be the issue? I don't know what is behind that bolt...

Thank you.
I always put plenty of flexible gasket sealer on the waterpump bolts when I install a new pump...at least one of the bolts screws into the water jacket allowing pressure to cause the coolant to leak past the threads and drip onto the engine .....then burp it(rookie advice).
Reply
Old Aug 31, 2014 | 08:35 AM
  #10  
Easy Mike's Avatar
Easy Mike
Team Owner
Supporting Lifetime
20 Year Member
 
Joined: Jun 2000
Posts: 38,923
Likes: 1,481
From: Southbound
Cruise-In II Veteran
Default

Originally Posted by fka466
...When i would take the car to higher speeds for long periods of time the temperature would rise quite a bit. Any thoughts?...
Define "quite a bit".
Reply
Old Aug 31, 2014 | 09:14 AM
  #11  
fka466's Avatar
fka466
Thread Starter
Heel & Toe
 
Joined: Aug 2014
Posts: 15
Likes: 0
From: Hampton VA
Default

Originally Posted by doorgunner
I always put plenty of flexible gasket sealer on the waterpump bolts when I install a new pump...at least one of the bolts screws into the water jacket allowing pressure to cause the coolant to leak past the threads and drip onto the engine .....then burp it(rookie advice).
Going to try that today. Headed to the store now to get some thread sealer. I burped it last night. Temp stayed normal until i got on the interstate. Once the coolant got past that bolt the temp crept up to about 230-240 and stayed there until i got home.

Will be sure to let you guys know what happens after today.
Reply
Old Aug 31, 2014 | 09:15 AM
  #12  
fka466's Avatar
fka466
Thread Starter
Heel & Toe
 
Joined: Aug 2014
Posts: 15
Likes: 0
From: Hampton VA
Default

Originally Posted by Easy Mike
Define "quite a bit".
Haha my bad. Noob mistake. It got up near the red line at some points. I would guess somewhere around 260.
Reply
Old Aug 31, 2014 | 02:04 PM
  #13  
fka466's Avatar
fka466
Thread Starter
Heel & Toe
 
Joined: Aug 2014
Posts: 15
Likes: 0
From: Hampton VA
Default

OK so here's an update. I removed the bolt that was leaking and put some thread sealant on it. However, after trying to burp the radiator it didn't hold. I tried burping the radiator with the leaky bolt with no success. Everything i tried failed. I followed the procedure below but could not get the temp below 200F.

Burp Procedure:

Start w/ a cold engine
Remove rad. cap
Idle for 1 minute
Install cap
Cycle RPM from idle to 3000
until coolant reaches 210F
Shut off engine
Remove cap
Start engine
Idle for 1 minute
Install cap
Cycle RPM from idle to 3000 until
coolant reaches 210F
Shut off engine
Remove cap
Top off

End Burp Procedure.


Right now I have the front end on jack stands. I pulled the leaky bolt again and swapped it with a new bolt all together. Before I put the bolt in the motor, I blew air into the hole to force coolant from the system. I then used Q-tips to dry the hole. I put thread sealer on the threads and gasket sealant on the shank. I still have the car on jack stands waiting for the sealants to set. While I was in there I went ahead and replaced the thermostat for a new 180F thermostat and put on a new water neck. As it sits, there is a lot of coolant missing, and a near full coolant reservoir.

Does anyone have any advice on how to proceed?
Reply
Old Aug 31, 2014 | 03:30 PM
  #14  
jcmurray52's Avatar
jcmurray52
Cruising
 
Joined: Aug 2014
Posts: 14
Likes: 0
From: Kansas
Default

Originally Posted by fka466
OK so here's an update. I removed the bolt that was leaking and put some thread sealant on it. However, after trying to burp the radiator it didn't hold. I tried burping the radiator with the leaky bolt with no success. Everything i tried failed. I followed the procedure below but could not get the temp below 200F.

Burp Procedure:

Start w/ a cold engine
Remove rad. cap
Idle for 1 minute
Install cap
Cycle RPM from idle to 3000
until coolant reaches 210F
Shut off engine
Remove cap
Start engine
Idle for 1 minute
Install cap
Cycle RPM from idle to 3000 until
coolant reaches 210F
Shut off engine
Remove cap
Top off

End Burp Procedure.


Right now I have the front end on jack stands. I pulled the leaky bolt again and swapped it with a new bolt all together. Before I put the bolt in the motor, I blew air into the hole to force coolant from the system. I then used Q-tips to dry the hole. I put thread sealer on the threads and gasket sealant on the shank. I still have the car on jack stands waiting for the sealants to set. While I was in there I went ahead and replaced the thermostat for a new 180F thermostat and put on a new water neck. As it sits, there is a lot of coolant missing, and a near full coolant reservoir.

Does anyone have any advice on how to proceed?


I see you replaced the pump and doing so replaced the coolant; check the coolant to water ratio. Too much coolant and not enough water can cause some of the issues you stated;

and it appears this is a cascading issue and you have covered most of them.
Reply
Old Aug 31, 2014 | 04:15 PM
  #15  
fka466's Avatar
fka466
Thread Starter
Heel & Toe
 
Joined: Aug 2014
Posts: 15
Likes: 0
From: Hampton VA
Default

Originally Posted by jcmurray52
I see you replaced the pump and doing so replaced the coolant; check the coolant to water ratio. Too much coolant and not enough water can cause some of the issues you stated;

and it appears this is a cascading issue and you have covered most of them.
OK sounds good. I just lost a good amount of coolant on the last repair attempt. I'll be sure to watch the amount of coolant i add with respect to how much water I add. Thank you.
Reply
Old Aug 31, 2014 | 07:20 PM
  #16  
BKbroiler's Avatar
BKbroiler
Le Mans Master
20 Year Member
Liked
Loved
Community Favorite
 
Joined: May 2002
Posts: 5,084
Likes: 786
From: Lebanon Township New Jersey
Default

I use this method to fill my cooling system and it never fails: With the car on level ground, radiator cap off and thermostat housing removed, fill the system through the thermostat location. Coolant will reach the thermostat level and the top of the radiator at the same time. Install the thermostat and housing. Start the engine with the rad cap off. Let it idle till the tstat opens and you see flow in the radiator. The level will drop slightly. Fill the radiator, put the cap on and put some coolant in the expansion tank. Your system will be full of coolant and virtually no air.
Reply
Old Sep 2, 2014 | 12:57 PM
  #17  
fka466's Avatar
fka466
Thread Starter
Heel & Toe
 
Joined: Aug 2014
Posts: 15
Likes: 0
From: Hampton VA
Default

Update:

The bolt penetrating the water jacket cured for almost 20 hours. The leak is now fixed.

As for burping the radiator I followed the guide found in the Haynes manual. With the car still on jack stands, I drained the reservoir tank to the cold line and added some coolant to the radiator. I also turn the heat to high and the fan to high as well. With the cap off the reservoir and radiator, I started the engine and let it idle to its running temp. When the thermostat opened I added coolant to the radiator and let the engine idle for a few more minutes. I would drop a little bit of coolant periodically into the radiator during this time. When I didn't see many bubbles coming to the top of the radiator, I placed the caps back on the radiator and reservoir with the engine still running.

This seemed to do the trick as far as burping goes. I was still getting some strange readings on the temp gauge however. After driving it around a while, I was still baffled as to why the motor would start running hot. At one point I stopped at a friends shop to take a look. Nothing out of the ordinary though. When I left the shop the temp shot to 260F within two blocks. I pulled over and popped the hood, again nothing strange. I started the car back up and it went straight down to 200F. This got me thinking that the new temp sending unit was acting up. Upon some research I found that the auto parts store temp sending units can be the wrong ones all together. I also found out that too much thread tape can cause grounding issues. I replaced the sending unit with the old one following the instructions I found, only taping the first 3 threads, and what do you know my temp hasn't gone over 200F since.
Reply

Get notified of new replies

To Coolant Issues

Old Sep 2, 2014 | 02:39 PM
  #18  
briankeery's Avatar
briankeery
Melting Slicks
10 Year Member
Liked
Loved
Community Favorite
 
Joined: Oct 2011
Posts: 3,453
Likes: 67
From: Midland Ontario
NCM Sinkhole Donor
Default

Well done, I think you're home free.
Reply
Old Sep 2, 2014 | 03:39 PM
  #19  
76CSRvette's Avatar
76CSRvette
Burning Brakes
 
Joined: May 2014
Posts: 1,094
Likes: 16
From: Los Angeles California
Default

Hence the old saying if it ain't broke don't fix. good job trouble shooting. I had to go with a 60s corvair trmp sending unit as it was closer to readings on gun and original was nowhere 6 be found as mechanics threw it away.
Reply
Old Sep 2, 2014 | 07:27 PM
  #20  
nivek1's Avatar
nivek1
Advanced
Supporting Lifetime Gold
10 Year Member
 
Joined: Mar 2014
Posts: 71
Likes: 1
From: Sonoma Ca
Default

Very good. Nice to figure out those nagging little buggers. Still working on some '68 only issues on mine. This is why we live right?
Reply



All times are GMT -4. The time now is 10:18 AM.

story-0
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2

Slideshow: Should you buy a 2020-2026 Corvette or wait for 2027?

By Michael S. Palmer | 2026-04-22 10:08:58


VIEW MORE
story-1
2027 Corvette vs The World: Every Model vs Closest Competitor

Slideshow: 2027 Corvette lineup vs the world.

By Joe Kucinski | 2026-04-20 17:58:41


VIEW MORE
story-2
10 Most Common Corvette Problems of the Last 20 Years!

Slideshow: 10 major Corvette problems from the last 20 years.

By Joe Kucinski | 2026-04-14 16:37:05


VIEW MORE
story-3
5 MOST and 5 LEAST Popular Corvette Model Years in History!

Slideshow: 5 most and least popular Corvette model years.

By Joe Kucinski | 2026-04-08 13:25:01


VIEW MORE
story-4
2027 Corvette Buyer's Guide: Everything You Need to Know!

Slideshow: 2027 Corvette buyer's guide

By Joe Kucinski | 2026-04-17 16:41:08


VIEW MORE
story-5
10 Things C8 Corvette Owners Hate (But Won't Tell You)

Slideshow: 10 things C8 Corvette owners hate, but won't tell you.

By Joe Kucinski | 2026-04-01 18:36:07


VIEW MORE
story-6
10 Best Corvettes Coming to Barrett-Jackson Palm Beach 2026!

Slideshow: Should you add one of these incredible Corvettes to your garage?

By Brett Foote | 2026-04-01 18:14:05


VIEW MORE
story-7
Every Corvette Grand Sport Explained! (C2, C4, C6, C7, & C8)

Slideshow: Every Corvette Grand Sport explained

By Joe Kucinski | 2026-03-26 07:13:44


VIEW MORE
story-8
Grand Sport & Grand Sport X Launch Alongside All-New 535hp LS6 V8!

Slideshow: Breaking down the 2027 Grand Sport, Grand Sport X, Stingray, and LS6 V8.

By Michael S. Palmer | 2026-03-26 13:48:45


VIEW MORE
story-9
5 Reasons Bad Drivers Crash & 5 Ways to Avoid a Costly Mistake!

Slideshow: 5 reasons bad drivers crash sports cars & 5 ways to avoid a costly shame!

By Joe Kucinski | 2026-03-25 16:32:55


VIEW MORE