last shot--high temps

[flatlander]

OK, I have tomorrow night to try to find the cure to my hi water temp situation.

I have done:
new stat
new coolant
coolant filter
working fan clutch
new hoses

Tomorrow I will replace the radiator cap. What's left to do?

Tonight it hit 225 idling with the a/c on, and I had to pull on the shoulder for a few minutes when it tried to climb to 250.

The symptom that led me to change the stat is when it's running 210+ and it'll all of a sudden (2 seconds or less) drop to 190. Sometimes it stays at 190. I think something is clogged, but where do I start?

 

[Exekiel69]

Maybe You already did this but I don't see if you replaced the radiator already. Some times it is an aftermarket radiator that is too small (not enough row's) or your's cloghed.

 

[squeekyM]

I do not want to steal your thread, but I am having the EXACT same issue. The only difference on my truck, is that I already replaced the radiator.

The only other thing I can think of is that the impeller on the waterpump is plastic and has deteriorated, causing less waterflow= higher temps. Let me know what you think. Thanks in advance.

- Jerry

 

[yARIC008]

If i remember correctly the water pump impeller is metal.

 

[catman]

HI I have seen impeller cracked on 2 3406 cats and 1 series 60 so it is a possility

 

[riphip]

Got a Ford pump here in box. Metal (don't recall seeing a plastic impeller on auto engines)

Was the ball in the t-stat neck loose or stuck. Should be loose / might be your problem.

 

[stiesel]

i'll just repeat what Exekiel69 said, clogged radiator.


by any chance have you replaced the heater core recently. my truck blew two heater cores before i noticed the radiator was clogged.

 

[flatlander]

Is there anyway to unclog a radiator?

 

[Agnem]

I've seen some cheap re-manned water pumps that looked like the impeller (metal) was going to fall off. Maybe yours did! You could find out easy enough by disconnecting your heater hose and starting the engine. If you get a bath, then na. That's not it.

 

[Timthetoolman]

I fooled around with my truck overheating while pulling my fiver for a year, I had two radiators, one from a donor truck, had both of them rotted cleaned checked, re-rotted and cleaned again and both still over heated.

This spring I had planed a trip of 1200 miles with the fiver and didn't want any problems so I changed my radiator out with one of the heavy duty ones from NAPA, problem solved.

With the new radiator and a MStech fan cultch I can pull in the Tennessee Mts. in 90 plus heat and never get over N on Normal or my manual gauge on the cylinder head over 200 degrees.

 

[krawlr]

When you say "working" fan clutch do you mean new? I've found the only way to be sure is to replace it with a new one or pin it. I've seen many show up at the shop with a whole catalog of new cooling system parts and still getting hot, replaced the fan clutch and all better. Customer goes , I go

 

[icanfixall]

You guys with the "new" radiators really need to look at the rows of tubes and the fin count. The higher the fin count on each tube, the better it will transfer heat. I just helped a member remove an original radiator in his 88 truck with a fin count of 12 fins per inch of tube and install a new radiator with 17 fins per inch of tubes. It was a 4 row core that had 76 rows counting from side to side as compared to the original radiator that had only 53 rows counting side to side. Yes... A bad fan clutch will create an overheating problem but you usually don't see this till you try to pull something. Then its too late.

 

[tonkadoctor]

Here's one test you can do. Wife won't like it but it works.


Take the thermostat and place it in a pan of antifreeze and place it on the stove with a calibrated meat or candy thermometer. Increase heat and watch for it to open and record the temperature it starts to open and the temperature it is fully open. If it's not in spec replace it.

Another thing I don't see mentioned is did you pull the drain plugs in the block and flush the crud and sediment out of it that builds up over time.

 

[82fordtruck]

When I got my truck, I fought and fought with this. Mine had bent over fins on the AC condenser, lots of mud and even dead birds between the concenser and the radiator, and then the fan clutch came off the inner chaft, ruining my radiator. The new fan clutch and radiator did a lot, as did the others.

I CAN still get it to overheat, but I have to be lugging the engine. Downshifting always cools it down, and it's obvious when that fan kicks in.

You've probably got a combination of problems, like I did.

 

[Mr_Roboto]

To add to the radiator fray, row count does not tell you anything.

Years ago I needed to replace a leaking radiator on an 86 F150. So I go to Murray's, a "Heavy Duty" radiator would take 2 weeks, they could have a 2 core the next day. OK.

Well I take this thing out of the box, this "2 core" radiator was as thick as a regular 4 core would be. The tubes were just very wide......

So be careful, a 4 core with itty bitty tubes won't do you any good...