Has anyone had any experience with;
Evans High Performance/High Flow water pump.
VHP Constant Monitor Fan Controller
B-Cool High Capacity Aluminum Radiator? I'm interested in these products. 97 C5 runs hot in traffic. Coolant expells from Coolant Tank Cap after engine shut off. Seems to run hot while in traffic, but runs cool enough at speed. Any suggestions concerning this issue is appriciated. Deployed to Persian Gulf, but want to orders parts to remedy nagging situation upon return to Sacramento (hot in Summer). Thanks.

 

First off is it a manual or automatic ?

Could be a number of issues, dirty radiator (common problem), thermostat, fans, etc ...

You'll need to do some investigation first before just jumping in and buying a bunch of parts.

 

They all run warm in traffic by design. How hot are you running? If you run up to about 230 in traffic and about 192-195 when under way, you probably don't have a problem. Maybe your overflow tank is overfilled. I would find and correct the problem, if one exists, before you start throwing parts at it.

 

It is automatic. Yes, it has high mileage. I replaced the Radiator a few months ago, installed by Corvette Shop in San Diego. It only heats up when I can't roll, and no air is passing through.

 

Can't speak to Evans or VHP or BeCool, but I can speak to Dewitt's radiators. I put one of their units in my car and had the fan temps also reset to a lower temp and a 160* thermostat and it runs great. Even in heavy stop/go traffic in mid summer I see approx 210-215 at most. Normal street driving in mid summer (both surface streets and freeways) my temps stay around 185-192*.

Btw, if your system experiences boil-over after shutoff you have some issue(s) going on. Could be partially blocked radiator or maybe a fan not coming on or possibly a faulty radiator cap, or some combination of the above. Btw, the replacement GM rad caps are now 18 lbs, not 15.

DeWitt's is a forum vendor and they run special pricing offers usually twice a year here on Corvetteforum. Not sure when the next one is but you can contact them. They were a pleasure to deal with. Excellent customer service.

HTH

 

In traffic, it gets up to 225, then the fans / or fan comes on. It will cool down to 117, but goes in and out, then back up to 225. Coolant overflows from coolant tank after I shut off the engine.

 

That "heat soak" causing some boilover makes me suspect a faulty cap and/or (as some has already stated) an over full surge tank. I fill my surge tank until the liquid is just under the little "cross hatch" bars inside the tank and I don't have any problems.

 

Lone Star,
What prompted you to replace with Dewitt's radiator. Could it be something as simple as the coolant tank cap, being the reasons it expells coolant? How did you lower the temperature that the fans come on? What temperature do they come on at?

 

Two reasons for DeWitts. I live in a very hot climate (high temps and high humidity = bad combination) and I upgraded to a larger engine. The fan temps can be reset by most any Vette shop that has a Tech II scan tool (required). I don't recall the specific fan temp settings right now. Even with my stock LS1 engine though, I never experienced boilover, but my temps were considerably higher than they are now.

Yes, a faulty cap may not be holding it's designed pressure any longer and if so, it will open (or "vent") at a lower pressure. Have you made a check for leaves/plastic bags/slow pedestrians up at the top of the front of you radiator as well? Our bottom breathering C5s like to suck things up from time-to-time.

Edit: Just checked my fan temp settings.
Fan#1 On @ 186* Off @ 176*
Fan#2 On @ 196* Off @ 186*

 

Lone Star,
I'm thinking Texas (hot climate), thanks for your inputs to all. I'll start with the 18 lb pressure cap. Does crud and debris collect inside the engine block, you know, that impedes the flow of coolant aroung the cylinder? Perhaps flushing the block will help. I thought it might be a good idea to replace the water pump, thermostat, I think it's all original.

 

How many miles on the car? Unless your cooling system has been really badly neglected over the years, I probably wouldn't be too concerned with crud buildup etc, although a flush and fresh coolant definitely can't hurt and is always a good starting point for servicing the cooling system. If your thermostat is only partially opening, it too can serve as a restriction to coolant flow. The factory water pumps on the C5s are pretty durable. Most guys I've seen posting indicate somewhere around the 90K to 110K mileage range before changing. My original LS1 pump let go (started seeping actually) at approx. 95K miles. If you do replace, use the LS2 (or from what I've heard LS3 as well) water pump. It is a direct bolt-on replacement plus it has the newer style thermostat housing that allows you to just replace the thermostat (only) in the future. Right now, if you were to replace your thermostat, you would have to buy the thermostat/housing assembly as they only come that way on the LS1 and can run anywhere from $50-75 range. If you change to the LS2 style pump, you will have to also by the correct LS2 thermostat housing (MUCH cheaper than the LS1) and thermostat too of course. I haven't seen any hard data, but it's said that these newer pumps are more efficient and have better flow, especially the LS3 version. Btw, I would recommend going new (not rebuilt) and try Gene at GMpartshouse.com or Bob at Fichtner Chev, both forum vendors. These newer style pumps do not require different length belts either. Personally I much prefer the Goodyear Gatorback belts.

HTH

 

LoneStarFRC is giving you some good advice. I had problems with mine after 170000 + miles when I replaced the waterpump with the new style offered from PACE. It started running hotter after that. The water pump came with the newer style thermostat. Cooling system has always been maintained. Mine was slowly losing coolant from the cap over time. I replaced the Rad cap which fixed that. I fixed the warmer temps by replacing the thermostat that came with the PACE water pump with a 160 Tstat from Tick in Mooresville NC. Runs great now. Still heats up in traffic but not like before. You know there is a trick I learned when doing this. Something about removing the little coolant bypass pipe under the throttle body. Then filling the radiator slowly until you force the air out. When you see coolant coming out of the bypass you know the air is gone and you can connect the little pipe back up and finish the fill. In my case it is a bypass. If the bypass hasn't been done I think the tube just connects to the throttle body......I've heard that trapped air will cause them to run hot too. good luck

 

I would look at getting the car fixed first, you obviously have an issue. The car getting up to 225 is normal but the overflow when turning it off is not. You are going to throw money down the drain trying to fix a problem by just throwing parts at it.

 

Wow, 170,000, that encouraging. Mine has 135,000. How long will these things run? I'll take it apart and replace the thermostat, make sure it's flowing like it should be. Is it possible that the water pump isn't working correctly, even though it's not leaking? I looked at the Dewitt Radiators on their web site. Twice as much surface area on the cooling fins. I like that. The engine would have to run cooler, wouldn't it?

 

I have seen water pumps where the impeller has completely deteriorated., nothing left but a small flat disk that was the center of the impeller.

 

Sounds like that was from electrolysis and it "ate" up the impeller. Short of being a severely neglected cooling system on the OP's car, I would seriously doubt that to be the case here.

 

Would that mean there are remnents/pieces of the impeller in the engine block? Or does it disolve. I guess my first move is to take off the water pump and inspect it. Thanks for you input.

 

Well, thanks for all the inputs. I'll strip it down to the water pump, and replace with a new one. I'll make sure to install a new themostat (170 degrees) and housing. I've seen a step by step DIY layout with pictures, and take my time to do it correctly. I don't think my cooling system has been grosley neglected, the car runs fine and everything works on it except it does not blow cold air from the A/C. The Dewitt Radiator really is "attractive" to me, in that if I'm going to go through all that, how could it hurt to add that upgrade. $620 would be worth it to me, to rid myself of this condition. Could it actually run to cool? I've read that the coolant temp should be around 195 as a rule, to burn off impurities and any water condensation in it. Thoughts?

 

Has the cooling system on this car been badly neglected? What is the apparent condition of the coolant? Do you get random "Low Coolant" warning messages on the DIC and have to add coolant periodically or does this message only happen after a "boilover" or two?

A water pump impeller being damaged or destroyed is extremely rare and should not be high on your list of suspects. It is grasping for straws. Besides, I thought your first move was going to be replacement of the cap.

Do this: have, or do, a cooling system pressure check. Have, or do, a pressure cap test. If not OK, replace. If pressure test is OK, drain, flush, and refill the system with fresh Dex-Cool and water (I use distilled .65 to .75 per gallon at the store). If cooling system pressure test is NOT OK, repair/replace the source of the leak. Remember: if you want to replace the thermostat because you suspect it being bad, be prepared to spend anywhere from $45 to $75 to replace it. If you DO replace the pump with the newer style, that expensive new thermostat you bought will NOT work on the newer pumps.

 

Be sure you check the simple stuff first. These cars collect a lot of debris in front of the radiator way up high. I get under the car once a year and pull out a lot of leaves etc. Maybe you'll be lucky and that is all it is.