At my wits end, motor getting hot. Input please

[lil hoodlum]

Hello everyone.

I haven't been much of a regular poster as of late. Life changes and all. Life changed for me again as of late. After nearly 17 years of employment, I was layed off. Business closing down.

Well my cocern is that I will likely have to commute to work as well the job search. My truck is my daily driver. I have been pretty forunate in that I haven't had but 2 or so breakdowns in the last 3 years. And unforunately I was involved in an accident a little of a year ago, so the old girl is banged up.


Ok, so my issue is that my motor gets really hot. Granted I live in Texas and it does get hot here, but I'm not too comfortable driving around with the motor @ 210 degrees. This is not a new issue however, it is not likely that I will live just down the road from work.

Specs:

350 sbc. Stock, and way too many miles on the rebuild 18 years ago.
3 speed manual
No A/C
HEI distrubator
ceramic coated headers
4 barrel Edelbrock carburator #1405, aluminum Edelbrock intake
stock heads
New 3 row Champion radiator
Stock mechanical fan with heavy duty radiator shroud.


I've been researching "overheating" threads posted on the forum and have found some good info. Now heating a wall though

Motor has recently gone up to 210 degrees before I pulled over to cool things down.

New sparkplug wires and sparkplugs, gapped @ .045

Cleaned out and rebuilt carburator. Drivers-side air-fuel mixture circuit was plugged up. Since cleared out. I feel that I have "enriched" the mixture thinking I might have been too lean previously.

Initial timing is 13 degrees BTDC. Vaccum advance is new and is in working condition. # AR10. Stock springs and weights in distributor oiled up and freely moving.

Recently replaced 3 inches fan spacer with a 1.5 inch spacer as I felt fan was too far in the shround.

Replaced thermostat with new 180 degree unit. Just for grins boiled the old one, which was a 180 degree unit and it didn't open up until 215 degrees.

I feel that the waterpump is working correctly as it does "pressurize" the radiator hoses.



Any ideas?

Something I may be missing?

[lil hoodlum]

more photos


Basically, the temp just steadily goes up and topped out at 210 degrees. Never done this before. Temp usually around 190 - 200 degrees. Heater core started leaking and I ran one of the hoses to bypass the heater core. I think that alone made to the temp go up 10 degrees.

[lil hoodlum]

Recent photos of the truck. Damage is to the bed only. Got "t-boned" on the passenger rear. Force of the impact "shoved" my truck to the drivers side into a car at a stop sign.

[Mmorgan32]

Might sound dumb and I have done it before not thinking about it, is your thermostat in the wrong way? I live in central California it's over 100 every day, I have a 180 and a 3 row champion radiator and mine temp barely gets warm. Or maybe silicon blocking the thermostat, or a clogged water port somewhere I had that happen on my nova it was in my intake where it mounts to my head just a big clog

[toolboxchev]

I know the feeling, getting on to solving this one myself.

A good 4 core brass and copper radiator is going to bring down the temp. Have you thought about the rust scale buildup inside the block? Those old Zinc plated steel water jacket plugs?

There is a method to my madness. Been getting it all corrected on the same problem. Send me a pm and I will give you my radiator source. Industrial NEW core for less than any store was offering in an everyday core.

[Boog]

Just to clarify, you have a four or five blade direct drive fan and not a clutch fan? It's hard to tell by the pics but it looks like the blades may still be inside the shroud. The optimum fan blade placement is 1/2 way inside and 1/2 way outside the edge of the shroud for proper air flow through the radiator and the blade diameter should be within about 1 inch of the shroud opening size.
Also are you using an aftermarket temp gauge?
With no accessories or auto trans there is no reason that new 3 row radiator can't cool your engine.
Has it gotten so hot it boiled over? Do you have to add coolant regularly?

[LSR]

One of the most overlooked piece in the cooling system is the pressure cap. Test it,dont just change it,and if you replace test new one also. Lately some new caps have been way off on the pressure they can hold.

[65standard]

Try a 170 thermostat and see if that gets you the 10 degrees you're looking for.

[cdowns]

have you changed the water pump recently? cause sometimes they will give you a reverse flow pump and that will give you problems

[Jason Banks]

I'm with Boog. It looks like your fan is entirely inside the shroud and it should be half in and half out.

Was this originally a 6 cylinder truck? If so does anyone know if the 6cyl engine mounting is further forward than the V8? That could explain why your further into the shroud.

I would flush the cooling system just to be safe and a water pump would be cheap to replace, just to know it's all good.

That's a good looking truck. I hope you get some good insurance money for the T-Bone....

[lil hoodlum]

I want to thank everyone for reading that massive wall of text and replying.


Water pump is the short variety and I do believe it is working as it pressurizes the radiator hoses when motor is running. When not running, easy to pinch the hoses close, not nearly possible when running. However I do have another new water pump in my parts stash.

Radiator cap is new, came with the new radiator. It is a believe rated at 9 PSI, but not 100% certain.

I am certain I have installed the thermostat correctly. Have installed it wrong before. LOL

I changed out the 3 inch fan spacer for a 1.5 inch one because it seemed the fan was too far in the shroud. New spacer hasn't had any affect on motor temp.

First pics with 3 inch spacer.
Other pics with 1.5 inch spacer.

[lil hoodlum]

Oops! Forgot to add pictures of new spacer.

[lil hoodlum]

At this point I think I have covered most of the common reasons.


It may very well be someting that I am overlooking or not correct on. New thermostat may not be working properly.


Motor is some 18 years on rebuild so there maybe a build up of scale or whatever inside. What does anybody recommend for cleaning it out?


There very well maybe a blockage some where in the motor, intake, heads, etc. I am not opposed to ripping the intake and heads to verify and install new head gaskets to rule out old ones leaking. Oil is not milky. Antifreeze/coolant is a nice green color.


2nd question.
Could valves be in need of adjustment cause a motor to run hot?

[lil hoodlum]

Originally Posted by Mmorgan32

Might sound dumb and I have done it before not thinking about it, is your thermostat in the wrong way? I live in central California it's over 100 every day, I have a 180 and a 3 row champion radiator and mine temp barely gets warm. Or maybe silicon blocking the thermostat, or a clogged water port somewhere I had that happen on my nova it was in my intake where it mounts to my head just a big clog

Doesn't sound dumb to me. Thank you for your suggestions. I have read so many replies to other threads where others like yourself I have reported similar set up like mine and they don't have the same issues as mine.

[lil hoodlum]

Originally Posted by Jason Banks

I'm with Boog. It looks like your fan is entirely inside the shroud and it should be half in and half out.

Was this originally a 6 cylinder truck? If so does anyone know if the 6cyl engine mounting is further forward than the V8? That could explain why your further into the shroud.

I would flush the cooling system just to be safe and a water pump would be cheap to replace, just to know it's all good.

That's a good looking truck. I hope you get some good insurance money for the T-Bone....

Original V8 truck. Truck didn't have a shroud when I bought it so long ago and I ordered one from LMC so long ago. Truck originally came with Heavy Duty radiator. I believe I may or may not have the correct one. My shroud measures 5 inches across.


Didn't get any insurance money from the accident as the accident was my fault. I have paid out a little over $11,000 to settle the accident claims.

[dirtyjim]

how old is your radiator?

[lil hoodlum]

Originally Posted by Boog

Just to clarify, you have a four or five blade direct drive fan and not a clutch fan? It's hard to tell by the pics but it looks like the blades may still be inside the shroud. The optimum fan blade placement is 1/2 way inside and 1/2 way outside the edge of the shroud for proper air flow through the radiator and the blade diameter should be within about 1 inch of the shroud opening size.
Also are you using an aftermarket temp gauge?
With no accessories or auto trans there is no reason that new 3 row radiator can't cool your engine.
Has it gotten so hot it boiled over? Do you have to add coolant regularly?

I have the original 5 blade direct drive fan, yes. No clutch. There is just around an 1 inch clearance around fan shroud opening.

Yes, I am using aftermarket temp gauge.

Hasn't actually boiled over. Just the motor is like some kind of heat sink though. It puts out alot of heat. You can just feel it radiating out when it is running or after shut off. Engine components are very hot to the touch.

I don't have to add coolant regularly with the new radiator. I did have to with the one I replaced as it had several pin holes in. Was like that for I say about a year and a half before I bought new one. I thought that the motor being very hot was because of the old one had the pinhole leaks. After I replaced it, no new change.


I do have to say the motor runs very well.

[lil hoodlum]

Originally Posted by dirtyjim

how old is your radiator?

I just replace it like 2 weeks ago.

Champion all aluminum 3 row core. Part # CC369

[toolboxchev]

Currently with mine, I have also found the vacuum booster is bad. Causing the engine to run rough, but barely noticeable.


I am sure that is not helping the cooling issue. Normally I have 19 inches of vacuum.

The only way I could be positive was by spraying soapy water all over it while the engine was running and having a friend step on the brakes.

[lil hoodlum]

Originally Posted by toolboxchev

Currently with mine, I have also found the vacuum booster is bad. Causing the engine to run rough, but barely noticeable.


I am sure that is not helping the cooling issue. Normally I have 19 inches of vacuum.

The only way I could be positive was by spraying soapy water all over it while the engine was running and having a friend step on the brakes.

Great suggestion. Vacuum leaks

My truck is manual brakes, so no booster. With the motor running, I sprayed starting fluid all around the base of the carburator, vaccuum attatchments, and intake manifold gaskets. No noticeable change of RPMs indicating a leak.

I am not 100% certain to the pressure rating of the new radiator cap. It maybe higher than I think. I say this because a little bit of coolant "weeps" around the chrome water neck and recently oil is coming up past one of the intake manifold bolts. Noticed that on the night the truck got up to 210 degrees.

[lil hoodlum]

Just for good measure, today I am going to install a new 160 degree thermostat. Will test for proper operation prior to installation. If it passes, I am going to drill 4 small holes near the outer diameter of the thermostat as I have read in other threads others have done this.

I will also refill system from the water-neck, not just the radiator part. Maybe there is some massive stubborn air bubble. LOL


Thank you everyone for input and suggestions.


Keith

[Stocker]

Some will disagree, but IMO there is nothing to be gained with a 160 (or even a 180) thermostat. It probably came with a 190 or 195 and assuming the t-stat is good, it will not cause or contribute to overheating.

Are you sure your 210 reading is accurate? Even if it is, that's still not overheating. Water boils at 212, and pressurized 50/50 coolant is closer to 230.

A couple suggestions. A coolant recovery tank lets you fill the radiator to the top, which means more coolant in the system, which may help it run a bit cooler. If you do this, you will also need a new cap for a closed system.

More importantly though, I would definitely replace that fixed-blade fan with a clutch fan. It will pull a lot more air through the radiator when necessary, and partially disengage when extra cooling is not needed. It's possibly the best improvement you can do to your cooling system.

[Security guy]

It's been a while since I've messed with the cooling side of things, but does your lower radiator hose have a spring inside it? I remember hearing that if it don't, the system can suck that lower hose together which doesn't allow coolant to flow. Just a thought...

[Sklptrljay]

Going back to the original post, you said you were too lean before. That will cause an engine to run hot. Also over time it can cause detonation, ruin bearings, and reduce internal oiling-specifically on cylinder walls.

[lil hoodlum]

Originally Posted by Sklptrljay

Going back to the original post, you said you were too lean before. That will cause an engine to run hot. Also over time it can cause detonation, ruin bearings, and reduce internal oiling-specifically on cylinder walls.

I'm not sure if the motor was having a lean condition or not to be honest. I just suspected that after radiator and thermostat change didn't yeild any results. It may very well have been lean as the drivers side idle mixture screw wan't response to any change. As I cleaned the carb out a 2nd time I discovered that side was in fact blocked. The blockage has been cleared and I have turned out the idle mixture screws out generously trying to avoid a lean condition, if one was in fact existant.


I fully admit I am a shade tree mechanic at best!


I took some photos of the old radiator that I just pulled out. It was perhaps 5 or 6 years old and as you can see there is some build up of "crud" around the outlet side.

The inside of my motor probably doesn't look any better in the coolant passages. I have properly flushed the system 3 times or so over the last 18 years of this motor life. I bought some Prestone flush/cleaner. Will give that a try and leave it in for 2 or 3 days and drive as normal. Then drain, flush, and refill coolant system.


Question. Has anybody tried apple cider vinegar (5% acidity) to remove build up in coolant system passage ways?