Chevy Impala SS Forum banner

Water pump woes - some basic questions

2K views 7 replies 5 participants last post by  angelo 
#1 · (Edited)
I recently passed 20 years of continuous LT1 B-body ownership and somehow have never had a water pump or optispark fail on me. Looks like my run has ended finally with the failure of the water pump on my 96 RMW (V08 equipped). I know this is b-body basics, but I wanted to confirm a few things and ask a few questions of the knowledgeable here.

The scenario:
I took the car on an out of town trip and on the way back it started leaking coolant. I had some with me so, I put what I had in (about half a gallon) and kept going. The temp gauge stayed about 3/8 the whole time at highway speeds, which encouraged me to keep going to try to get back into town. When I did get into town, I stopped to buy more coolant and it was leaking but good. Temp still staying under half, but a few miles down the road it was creeping up. A few more miles and it was hitting 3/4. I stopped at a convenient place to see if adding more coolant would help. It hit the red at idle and I shut it down immediately. The coolant had just started to boil. I was still 33 miles from home, but at least I was in town and a tow was feasible and friends could take my family home.

- I know I pushed it, but I really didn't want to be dead on the side of the road out of town. Is it likely I damaged the engine running it that far? Did overheating briefly at idle damage it?
-The car starts and runs fine with the engine cooled off. I drove it off the tow truck and into my garage.
-I've read the stories of failed water pumps taking out the optispark. If the car is running well does that mean the opti is still good?

I am pretty sure the optispark is original, as the car has 112k and I bought it at 78k. I'll be replacing the water pump, and I've heard it said often that you might as well replace the opti while you're there. Do you all think that it would be worth it to replace a functioning 112k mile OEM opti? I've seen references to replacing just the cap and rotor. Is this recommended at the very least? What is the best brand and source for these?

Water pump questions:
-Reading through old posts, it sounds like the Gates water pump is a good way to go. ($60 from Rock Auto, they also have a $96 ACDelco).
-It also sounds like the water pump/optispark shaft seal should be replaced with the FEL-PRO Timing Cover Gasket TCS45956. Is that still the best source?
-Replacing that seal requires a special tool. I found a couple tools on ebay for $17-37, one included the seal also. Would that be the best way to go then? Is there a good way to do it with a homemade tool or common tool? Is that seal the only thing needed with the Felpro gasket kit, or do you still need all the other gaskets?
-Replacing the pump sounds like a big but not gigantic job. Any good tips from those who have done it?

I don't rely on the car for daily transportation (as long as our other 2 cars are working), so I can take the time to get the right parts and prepare for the job. Any help is greatly appreciated!
 
See less See more
#2 ·
I recently passed 20 years of continuous LT1 B-body ownership and somehow have never had a water pump or optispark fail on me. Looks like my run has ended finally with the failure of the water pump on my 96 RMW (V08 equipped). I know this is b-body basics, but I wanted to confirm a few things and ask a few questions of the knowledgeable here.

The scenario:
I took the car on an out of town trip and on the way back it started leaking coolant. I had some with me so, I put what I had in (about half a gallon) and kept going. The temp gauge stayed about 3/8 the whole time at highway speeds, which encouraged me to keep going to try to get back into town. When I did get into town, I stopped to buy more coolant and it was leaking but good. Temp still staying under half, but a few miles down the road it was creeping up. A few more miles and it was hitting 3/4. I stopped at a convenient place to see if adding more coolant would help. It hit the red at idle and I shut it down immediately. The coolant had just started to boil. I was still 33 miles from home, but at least I was in town and a tow was feasible and friends could take my family home.

- I know I pushed it, but I really didn't want to be dead on the side of the road out of town. Is it likely I damaged the engine running it that far? Did overheating briefly at idle damage it?

No. And, no. LT-'s a lot tougher than what little overheating you did. Just replace the thermostat. It's dead. Next.

-The car starts and runs fine with the engine cooled off. I drove it off the tow truck and into my garage.
-I've read the stories of failed water pumps taking out the optispark. If the car is running well does that mean the opti is still good? In short, yes. 112K is not really a mandate to go screwing with the opti if it's really running well. You got lucky and the 1 hour or so getting dripped on and then drenched apparently did not succeed in getting AF inside it. BUT, - 112k is perfect miles for a tune-up. And for plugs and wires.

I am pretty sure the optispark is original, as the car has 112k and I bought it at 78k. I'll be replacing the water pump, and I've heard it said often that you might as well replace the opti while you're there. Do you all think that it would be worth it to replace a functioning 112k mile OEM opti? I've seen references to replacing just the cap and rotor. Is this recommended at the very least? What is the best brand and source for these?
Yes, perfect miles for a tune-up. Search fro best brand and currently best mailorder house. There seems to be a good run currently (a certain type of AC Delco?) supposedly with copper contacts and thick heavy phenolic cap that won't deflect. Whatever you do, do NOT give up that original Mitsubishi optic sensor. Leave it alone. Locktite every screw. Take it easy removing the recessed tiny Torx screws.


Water pump questions:
-Reading through old posts, it sounds like the Gates water pump is a good way to go. ($60 from Rock Auto, they also have a $96 ACDelco).
-It also sounds like the water pump/optispark shaft seal should be replaced with the FEL-PRO Timing Cover Gasket TCS45956. Is that still the best source?
Yes. - It sounds you're describing the whole front engine kit. And the opti o-rings foir opti and WP are different.

-Replacing that seal requires a special tool.
I use a Sharpie cap.

I found a couple tools on ebay for $17-37, one included the seal also. Would that be the best way to go then? Is there a good way to do it with a homemade tool or common tool? Is that seal the only thing needed with the Felpro gasket kit, or do you still need all the other gaskets?
-Replacing the pump sounds like a big but not gigantic job. Any good tips from those who have done it?
Yes, read at least a 1/2 dozen of the threads that cover the R&R in detail - with hints.


I don't rely on the car for daily transportation (as long as our other 2 cars are working), so I can take the time to get the right parts and prepare for the job. Any help is greatly appreciated!

Good luck, and keep apprised of progress.
 
#3 ·
Yes. - It sounds you're describing the whole front engine kit. And the opti o-rings foir opti and WP are different.
96 Black


?
What is the correct opti O-ring if not the same one as the water pump?



I was poking around for parts and found the parts list for the Fel pro TCS 45956

Its a gasket set that contains:

2-407 O ring (water pump shaft)
1-14842 Timing Cover Seal
2-35072 Water Pump to Block
1-95579 Timing cover
1-95644 Distribuitor Drive shaft seal (big seal for opty opening)
1-95589 Water Pump Bearing Seal (The first seal from top to bottom)


The 407 O ring is also listed as a valve stem seal in a engine so it seems to be good for heat and oil resistance.


The Fel pro TCS 45956 and two 407 o rings(for the opti) seem like a good opti install kit.
Z09B4U Post #34,


https://www.impalassforum.com/vBulletin/34-engine-problems-maintenance/1308385-optispark-o-rings-10474278-discontinued.html
 
#4 ·
OP

Your 112k mi OEM opti is only in need of a new cap & rotor just like any SBC at 100k mi. There is a C&R kit at Rock Auto that has "brass" terminals. It is one of the more expensive ones on their site. Your Opti "may" have either coolant or oil in it. Just carefully clean it with Q tips, etc once you disassemble it and install a new C&R

I would either buy the seal "tool" as, IMHO, works better than home made versions or using a long socket or the WP drive spline for 2 reasons. 1. it is tapered so the seal lip is way les likely to fold over. 2. it is short so you can then nut a larger deep socket (size the width of seal) over it to drive the seal flush then remove the "tool"

Mechanical WP...they are a crap shoot on which one lasts longer. The cheap "lifetime warranty" ones are crap and even though they are free its your time to R&R them. FWIW I have had a EWP on for 20 years now

Get Permetex "waterpump & thermostat" RTV and use a skim coat on each side of WP gasket. Use thread sealer (read not loc-tite) on the lower DS WP bolt threads as it goes into a water passage.

The FelPro timing cover gasket/seal kit is what you want. You won't use all of them. DO NOT use any oil or grease on the WP drive or Opti seals. Install them dry. They are PTFE seals and despite some threads & videos showing people oiling these seals do not do it.

I would also replace the Opti seal. The crank seal is very likely fine but if there are signs it is leaking than replace it.

You do not need to remove the damper hub to R&R WP. Just the damper itself

Remember to bleed the air from the cooling system when you are done

Do not use Opti bolts to draw in the opti. Opti should sit flush against timing cover with just hand install

I don't think you did any damage to the motor from your over heat description

Since you are doing WP, consider condition of radiator, hoses and replace if needed (read if hoses are original replace them). Good idea on thermostat also. LT1 uses a specific T stat
 
#5 ·
[From ZO9B4U]
?
What is the correct opti O-ring if not the same one as the water pump?
[From ZO9B4U]


Oh boy - My original cocked up wording:
And the opti o-rings for opti and WP are different.

Correction:
"And the 2 O-rings for input spline shaft are different from the one for the WP."


https:https://uploads.tapatalk-cdn.com/20171108/73714eb8e8e0c7f6c714d2c0d69ebd7a.jpg


They are viton, not rubber - and get no lube for some reason. This thread speaks of them. It appears to be from the same thread ZO9B4U refers to:
https://www.impalassforum.com/vBull...-optispark-o-rings-10474278-discontinued.html


The one o-ring for the WP appears to be simple rubber by comparison. Referred to here at 2:22:


Note: Each new Felpro kit I buy has been packed different. I got one set with the 2 WP gaskets and 2 black o-rings in the same baggie when only one is needed. But there were no other O-rings, and certainly nothing looking special for the spline shaft. Another set came with 2 expected plasticish viton O-rings for the spline shaft, but zero others for the WP.
 
#6 ·
The 407 O ring is also listed as a valve stem seal in a engine so it seems to be good for heat and oil resistance.
Z09B4U


The 407 O ring is a valve stem seal used in jeep engines from the willys jeeps till chrysler took over. It experiences high engine heat and oil. Does it mater if we know what it is made from?


When I was in the injection molding industry 1%-5% carbon black would make any mix of re-cycled material black. The color of a part has nothing to do with it's material properties. For example silicon coolant hoses can be made in colors or black.
 
#8 ·
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top