jmgtp

I’m in the process of cleaning the block. I’ve got 1 bank pretty close to done. I tried using just a scotch-brite pad and carb cleaner but was literally getting no where. So I went with a razor blade first and got the bulk off then I ended up using a very fine stainless steel wire wheel on a dremel. I used almost no pressure at all and let the tool do the work, it still took quite some time but I was able to remove all the gasket material. I threw shop towels onto the valley to protect it and I taped off the gap between the cylinder walls and pistons to avoid getting any grit between the two. When I’m done prepping the block I’ll be vacuuming, blowing out with compressed air and wiping clean with alcohol impregnated blue paper towel to ensure the bores are clean.

So just how CLEAN does the block need to be? It seems there is an indefinite supply of filth on there. No matter how many times I wipe it with an alcohol soaked blue paper towel it comes up dirty. It is smooth, there is no gasket material left, but it isn’t shiny new. It looks stained, spotted and dirty and if you rub a bare finger on it will leave a smudge on you. Should I just keep at it with the alcohol & blue shop paper towel until it comes up clean?

I also acquired a thread chase – which is something I neglected to do last time. I’m basically trying to leave no stone unturned this time around. I have a new 3 core all aluminum radiator and new 160 degree thermostat on the way. I've ordered Victor Reinz head gaskets and I still need to order new hoses and intake gaskets. Also having a whole lot of trouble finding good old green coolant. Places only seem to sell yellow 'mix with any color' or dexcool equivalent.

Black89Z51

Get the yellow Prestone extended life stuff if you can't find the green stuff.

As far as the head surface, it should be pretty clean. Now that you've gotten most of the gunk off, use some cleaner and scotch-brite pads. Just be try to pack the cylinders with some rags so the grit doesn't get jammed between the piston and the cylinder wall.

leesvet

Inframes are difficult to do with a high degree of cleanliness...almost impossible unless you steam cleaned the engine prior to disassembly. Even them...crud reappears.

What I've learned to do thru similar trials is to get everything that you can see and feel. Do your assembly and fill the radiator with water ONLY and fill the engine with a cheap oil that you can drain after a few hrs or miles of running.

Drain the "start-up fluids" and refill with your usual quality liquids.
The liquids always collect the contaminants and by draining after a brief run time you get them out of the engine for good. Waiting for the oil filter is a huge mistake...since the majority of your oil is bypassed and does NOT go thru the filter...these contaminants will continue to circulate and form sludge mixed with wear particles...so the start- up flush collects them and the drain plug removes them...

leesvet

[QUOTE=93 ragtop;1580639608]I don;t think the current wiring arrangement IS the source of the problems either. My comments and ideas on the wiring were more to assure there was not a problem in other areas, knowing how sensitive the system is to voltage and resistence. IMO to assure that there was no possibility of corruption in the electrical, I'd wire it to an 'always on' circuit and isolate the FP from the WP.

jmgtp

Good news...heads pressure tested ok and I was told they warped only the tiniest bit. I have them back, clean and resurfaced. I spent last night doing more prep work on the block. I have the deck as clean as I can get it. No trace of gasket material and then I cleaned thoroughly with alcohol and lint free rags. I chased the bolt holes and was shocked to see just how much gunk comes out. Can't believe I didn't do that last time, I'm sure it threw the torquing of the head bolts off. Threads are nice and clean now.

I need to reassemble the valvetrain and I'm still waitin on a few parts to arrive. Should be easy reassembly from here on out.

jmgtp

Motor is mostly back together, all that remains to be done is the drivers side header, adjust the rockers, bolt the intake up, rocker covers wiring etc.

This morning I removed the radiator and installed the aluminum 3 core. There was nothing but a half dozen dried up leaves under the shroud. The radiator I pulled out is less than 4 years old and still looks essentially new. That said, I don't regret getting the 3 core but I have no doubts that the radiator I removed is perfectly good. I also repaired my steam tube that I broke. I cut the broken section out and repaired by adding a bit of tube. I used brake line fittings/unions - worked out well and no leaks (nice thing about the e-waterpump is you can run it with the engine off and not even fully assembled at that). I also found some rubberized oil pan drain plugs to replace the original washers.

Here is a question... A long time ago I eliminated the coolant tubes to the throttlebody. I removed the hoses and capped off the tubes on the radiator hose. Is this a guaranteed way to trap air? I believe the throttlebody also incorporated a bleed screw. Without the connection of those two hoses and the bleed screw is this guaranteed to cause an air pocket? If there is a chance that it can cause a pocket I'll reconnect to the throttle body.

aminnich

There is no bleed screw on the throttle body on the 95-96 LT1/4s, so doubt you would have any problem.

jmgtp

I don't think so either, but I'm now considering adding a tube (not to the TB) to connect these two together again. I can add a T with a bleed screw as well - it can't hurt to have one more spot to bleed air from.

MK 82

The myth will not die! There is no low oil press cutoff of the fuel pump an any C4 from the factory.

MK 82

Don't bother. That coolant passage is entirely separate from the induction system. You can leave it open with no ill effect.

mistaben

[QUOTE=93 ragtop;1580598894]hmm... this sounds plausible for my situation or it is picking up air in block some how... i would hope it is not an exhaust leaking into readiator issue, haven't yet gotten any test strips though to rule that out.

Scootin_Z

So what ever ended up happening here? did you figure out what it was? I feel like I just read a book and someone tore out the last page! lol

hiperf454

I am having the exact same problem but no electric water pump. My car sit for a year. Now its back up and the stat stuck. I flushed the radiator block. It over heats slowly idling and when i take it on the highway and kick it in the *** it over heats big time. i blew out the radiator with an air hose. Changed the stat. Used a vaccum assisted filler. So do I need a radiator ? I have an 03 Z with a magnacharger. BTW I checked for blown head gasket with the blue fluid tester and it showed no signs of blown head gasket. ? Any help would be appreciated.

WW7

This is what alot of guys on here do, and it's really unfair to everyone that helped and to those that read this thread looking for help...If your going to get help on this forum at least have the decency to get back and let everyone know how the problem was solved.......WW

PS..I just PMed the guy that started the thread ( jmgtp) asking him to reply with a post letting everyone know what finally happened ... Let's hope he responds....WW

jmgtp

PM received. You're right. I took advantage and didn't add anything to benefit others. That's my bad and I'll strive to do better in the future.

Please excuse any typos as this was written on my phone-

The problem I had was air in the cooling system. Though I never conclusively found the cause, I suspect it was the radiator possibly leakin at the plastic end tanks or taking in air at that point as the system cooled after shutdown. At 20yrs old, I replaced nearly everything cooling related - radiator, hoses, thermostat, etc. it fixed my problem. I know that's not a great answer but it's what I did. I figured these components had served their useful life and it made sense to replace them all now rather than have another overheatin issue.

To the member with the cooling problem currently - start off by bleeding the system. If you have air in there it will certainly show these symptoms. Beyond that, it's a matter of finding how air got in tree and replacing the failed component, or do as I did and refurbish the entire system with hope that any failed or soon to fail parts will be replaced.

desertmike1

There are many things that can cause an over heat, as you probably already know.. but the number 1 check is a clean un obstructed radiator.. [inside, and outside] followed by a cooling system that will pressurize to 15psi. Remember water boils at 255°f @ 15psi, anything less and you overheat (Boil). So even the smallest leak can be a problem..

hiperf454

Thanks for the response. I found that my cap did not have a gasket on it? That was really weird. I got a new one for 5 dollars. Then I flushed the radiator from the back to the front with air first then with the hose. It looked like grass was sticking out everywhere. I flushed the condensor and the intercooler several times until the grass sticking out was to a minimum. I just put it back together. I did notice that even using the snapon vac assist cooling filler, when I pulled the upper radiator hose it had nothing in it. So who knows. I might just say screw it and let it sit for another year and start selling off all this C5 and C6 parts. Thanks for the response gentlemen.

c4zf6nut

My 89 L98 had a similar experience to the posters over the weekend. I was returning from TuvTurk inspection which the car passed. Got on the highway, tipped the gas and the pedal stuck. Turned off ignition to kill and hit the brakes. Then, turned on and continued for a mile and took an exit to another freeway. Noticed temperatures creeping up from 230F to 240s. Pulled to the emergency/breakdown lane, turned off the engine, saw temperaturs shoot up to 250s and the red lamp came on. Lifted the hood. Coolant was boiling over the overflow tank. Tried a few other times to turn engine on, but temperature would immediately start creeping up from 240 up. Waited for tow truck, and when coolant temperature went down to 180s from 250s. Idled for a minute, saw the temperature was only going upto 190s. Decided to take a chance and get home about 10 miles away. Temperatures crept upto 235-240 range even while moving. I found an American car repairshop, mainly Jeep/Chrysler but also GM and Corvette business. They looked at the situation, told me my coolant was low several quarts. I told them that was the coolant which boiled over. They could not see any problems and the fan turned on, hoses are a few years old, radiator is a Silla double row all Aliminum which was installed two years ago. I had the radiator area cleaned. Frankly, stock radiator would have been fine since we cleaned both inside and outside of that radiator. Silla radiator is about 1 1/4 wide so water passages are likely way smaller. There is a new high performance 180 degree smart thermostat. When it was installed with a new thermostat gasket, I noticed the housing was little warped, cracked and repaired and there was no thermostat. I wonder what could happen to a thermostat housing for such damage. (crashed????)

I need to check for leaks there but there was nothing visible.


I did not play with the fan turn on temperatures. Last weekend, I tried to connect ALDL connector to my notebook and run TunerPro. While trying different jumper settings, there were some where the fan would turn on.-) I wonder if I messed up ECU and fan in the process.

I wonder if they could be blocked with gunk in the cooling system. In the TuvTurk ispection, they asked me to turn on heat and frankly I never turn on the heat. Any junk in the heater core may be released.


I suspected the temperature sensor for the fans. However, this is probably air getting in the system somewhere after coolant is lost. I just happened to have problems with cylinder 3 and cylinder 7 injectors. When we took them out, injector tips were a little rusty but spark plugs were not squeaky clean like steam cleaned. I thought it could be water in the fuel or lack of use. I wonder if there is a small head gasket leak there. A friend of mine told me to check out freeze plugs rot over time and those could be leaking very slowly. Any ideas?


The car was sitting for nearly a year, with small trips to charge the battery. I had noticed high temperatures and found that 5 quarts was missing. I added premixed regular old eth glycol antifreeze, and the overall ratio was 30%. There were no leaks under the car.

hiperf454

I bought a really kick *** aluminum radiator from Engineered cooling products and it worked great. Had the wife help me and we changed it out in about 20 minutes. Slick installation and 268.00 later I have a 2 core all aluminum radiator. I retuned the car and tested it on a 100 degree day. 174 on the guages. I have a 160 stat and the fans come on early. It ran almost 190 in traffic. I also have an intercooler that sits infront of the condensor too. Im running an intercooled magnacharger. Which builds some heat when run hard but I never see it on the guage.

radiator

first of all! Why the hell would anyone put an electric water pump on. Two problems with that alone if you get low on coolant the pump transfers heat to the motor, this in turn burns off the insulation on the windings now you have a less efficient motor. Now it takes more juice to start it and it is not as efficient as before. Then you have it wired to a circuit that is already designated for something else. You act like these upgrades can't fail. If it is such a great idea then why didn't chevy think of it. These guys build, design and engineer these engines for a living. The whole idea of the new pump being driven by the cam is so if the belt fails your car doesn't overheat. Electric motors fail so does the reeds in the pump and there is no sensor telling you that. Do you know that restrictive flow your pump can suck a hose flat eliminating all flow then Bam! The pressure is released in the other direction when it reaches boiling point.