Thread: Delayed overheating problem

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Originally Posted by rspears

The old one seemed to be sticking, so why would you consider re-installing it? Throw it away!! If you get the engine warm before you open the drain cock on the radiator the coolant will drop below the water neck and you shouldn't lose much at all. If you drain it cold the t-stat will be closed, and the upper hose will tend to hold coolant. With the hole it doesn't matter, it'll drain back either way, but slowly.

Originally Posted by 34_40

I wouldn't do a thing!! Until I verified with some separate tool what the temperature really was! I think you gauge is "off"..

Beg, borrow, buy a temperature gun that uses a laser, that's the easiest that I know of - for taking temps while the engine is operating.

Bring it up to full temp and then measure at the t-stat housing, the hose, the top tank of the radiator and then the bottom.. compare with your dash gauge.

Originally Posted by glennsexton

Great thread and let me also add my welcome to you megamax. I would second those who have appreciated your polite and positive attitude. It goes a long way here as many of us are old guys and well – we just prefer polite rather than rude behavior!

A couple thoughts from an ol’ Chevy guy who’s built a lot of small blocks and worked through any number of heat related issues:

1. They guys here recommending mechanical fans are spot on. The GM boys have done a lot of research and there’s no better cooling method than the stock GM fan and the stock clutch. If you can go to a wrecking yard and find the fan, clutch and shroud from a pre-1982 Camaro V8 you’ll do well to replace everything. Even a 40 year old clutch is probably fine; however the fan clutches from NAPA are functional replacements, usually made by Hayden (the originals were made by Eaton and Schwitzer). If there are any signs of leakage or the bearing wobbles replace the clutch – about $50 from a parts house. But the one for A/C as its heavy duty.

2. Get your timing set – Summit, Jegs and your local parts house have the timing tabs for less than five bucks. Start with initial timing 8-10 degrees advanced, vacuum disconnected, total timing should be 33-36 degrees with the vacuum connected @ 2000-2500 RPM.

3. Your negative battery cable looks kinda funky. Remember this is the electrical path for everything on your car and the starter draws 100-125 amps on a stock engine. Remove the cable and clean the ends really well on your wire wheel or with sand paper. Also grind the bracket to bare metal and attach with a 5/16” bolt and nut with star washers. Use a nice new Grade 5 and reef on it good and tight. Make sure the positive cable is real clean as well!

Keep up the great posts and once again, welcome to CHR

Best,Glenn

Thanks for the replies everyone! And sorry about the delay, have been really busy lately with the semester coming to an end.


rspears:
Ah good point, I'll throw it on my wall of dead parts in my garage (where all dead car/dirt bike parts go, it looks like an engine exploded all over my walls in there). I appreciate the advice for draining the upper hose too, I think there's still some residual small puddles of coolant in the garage that I can't reach with a mop.


34_40:
You know I think you've nailed it, even when the thermostat was sticking, but eventually get to the optimal point on the temperature gauge, when I would shut it off it would have a "rough" cut off (and this is after running it optimally for about 10 minutes). And also, occasionally, fire again even though the ignition was off, which I assume is autoignition of the fuel because the block was too hot. Perhaps this is also the reason that hot starts were so sluggish, and even more-so, perhaps the reason (or one of the reasons) why my old starter failed. Because now it sounds perfectly normal when I shut it off, and no longer have any problems with hot starts. Additionally, I find it hard to believe that an engine can run 120 F is a 70 F climate, although this is just an assumption. Honestly, if my temp gauge has been malfunctioning, I truly shudder to think how hot it has been getting the past year or so.

I posted an ad on Craigslist asking to borrow one of those infrared thermometers, even offering to pay a couple bucks to use it, so hopefully someone responds. I appreciate the advice, I think this might be it.


glennsexton:
Thanks for the warm welcome! I appreciate it, and you guys absolutely deserve the utmost respect for the great advice you give to people (including me!).

I do still have my old fan, but the cost of shipping would probably make it not worth it. I'll take your advice and check out a junkyard, I think I would definitely much rather have a stock GM fan rather than these wimpy flex fans.

I actually had no idea they carried timing tabs for so cheap, tomorrow is my day off so I'll go buy one for sure. It would be great to actually know my timing, plus I can finally use that timing light. When you say vacuum disconnected, do you mean the vacuum hose that leads to the vacuum reservoir?

I took your advice to take the negative battery cable off the bracket and sand it down and was pretty surprised to see how much paint was underneath it, most of the actual connection must have been through the bolt. So I sanded it down and put new hardware on it with the star washers as you recommended (which by the way, what is the significance of the star washers? Is this because the 'star' portions bite into the metal?), I then rubbed some dielectric grease on the outside in an attempt to prevent corrosion, and haven't had any starting problems since, in conjunction with also changing the thermostat. The whole car seems to run way smoother too.

Excellent thread!! Really enjoy reading all the thoughts and responses without the bickering!! megamax42 thanks for your follow ups,this will help others in the future that have similar problems!! Great knowledge on this site!! Thanks Pete

Originally Posted by megamax42

..... When you say vacuum disconnected, do you mean the vacuum hose that leads to the vacuum reservoir?

......which by the way, what is the significance of the star washers? Is this because the 'star' portions bite into the metal?

I agree, a great thread with lots of good information flow. On your two questions, the star washers ensure a better "bite" between the cable end and the base metal. If you only have one put it on the bottom, between the base & the cable end, IMO. On the vacuum line and setting the timing, you want to disconnect at the distributor and plug the line. A golf tee works great for plugging the line.

I hope that you choose to stick around and participate, offering advice where you feel you're adding value or asking questions if you don't understand what's being asked/answered. It's all good!!

Yup - what Roger said!!

YEP.. what he said!

Remove the hose from the distributor vacuum canister, plug the leak, and with engine at normal operating temp and at idle, verify the initial timing setpoint. I like to set mine at 10 degrees btdc (before top dead center). And if your interested, slowly raise the rpm's and watch the timing tab and the damper timing mark, see how high it goes and when it stops rising, make a note of the rpm if you have a tach attached and note the highest reading btdc.