I hate it when this happens!

[LubeDude]

I have a 1993 Ford Ranger 4X4 with a 4 liter 5 sp. Its been fine, but it tends to over heat a bit when I tow my boat up long hills. Mind you everything was fine except for that. So today, I figure I will put in a bigger radiator, (Two rows insted of one), I buy a radiator for an automatic with air, new hoses, new coolant, new serpentin belt. Temp now goes up and down, up and down, not too hot, not too cold, takes about 20 seconds to build up, and about 10 seconds to cool off, replaced the thurmostat but it still does the same thing. Whats up with this?

 

[Boomyal]

Re: I hate it when this happens!

Stop by Costco and get one of those infrared thermometers, $68.00 please. I think you have electrical fluctuations on your guage or sending unit.

 

[Skinnywater]

Re: I hate it when this happens!

Here's my test for the fan clutch.<br />Bring the engine up to a sure operating temperature. Actually the hotter the better.<br />In park with the brake set bring the engine up to 3,000 rpm and hold steady. Turn off the ignition while at 3,000 rpm. The fan should stop spinning quickly, within a second or two after the engine quits. Repeat the this test another 4-6 times.<br />If the fan should continue to spin several seconds after the engine quits, it should be held suspect.<br />Especially if the fan clutch is caked with oily dirt. This would indicate the viscous fluid is seeping from the coupler.

 

[LubeDude]

Re: I hate it when this happens!

Originally posted by Skinnywater:<br /> the fan clutch.<br />

Just replaced it last month. Also, it wasnt doing it before I changed the radiator.

 

[ZmOz]

Re: I hate it when this happens!

Maybe the thermostat is bad. It's not uncommon for them to be bad right out of the box. Did you get a $3 stat or a ~$12 stat? I just put a new one in my Jeep, and I think it's bad. It takes much longer to warm up now than it did with the old thermostat.

 

[LubeDude]

Re: I hate it when this happens!

Originally posted by ZmOz:<br /> Maybe the thermostat is bad.

Well, its like I said, it didnt do it with the old one with the old radiator, although it was a bit more extreme with the old thermostate and the new radiator. Bought the new one from Ford, now it has a tighter margin. Maybe its not a real problem. Ill see how it acts on the freeway this weekend. Maybe the new radiator is so big that the water cools way down, then when the thermostat opens, it cools too fast.

 

[ndemge]

Re: I hate it when this happens!

ah heck, just take that there tstat out for the summer runner wide open

 

[BoatBuoy]

Re: I hate it when this happens!

Here's my Ranger story. About 6 years ago, the temp guage would occasionally jump to the hot peg. I had a drip from my water pump, so I put a new one on. Same thing. <br /><br />I flushed and refilled the radiator and put in new t-stat. I also went from 195* to 180*. Same thing. <br /><br />I then removed the radiator and took it to radiator shop for rodding and cleaning. I re-installed it. Same thing, the temp guage would occasionally peg on hot.<br /><br />Also replaced the temp sender. No help.<br /><br />Finally, I bought a mechanical temp guage for about $15, installed it and found it was running at right temp. Seems the dashboard guage was faulty.

 

[kenimpzoom]

Re: I hate it when this happens!

Did you somehow have some air trapped in the cooling system.<br /><br />Also, maybe try drilling a small hole in the thermostat, to let water slowly flow even when the stat is closed.<br /><br />What thermostat temp do you have, and what is the proper thermostat for an automatic equipped truck?<br /><br />Ken

 

[Kenneth Brown]

Re: I hate it when this happens!

I'm with Ken. You have air trapped somewhere in the system. Drill 2 1/8 holes on the tstat and time will fix itself.

 

[LubeDude]

Re: I hate it when this happens!

No, there is no air, and it has the vent hole already in it, I filled it slowly with the engine running and the heater wide open. Its a 190 degree. If I just had an idiot light, I wouldnt even know.

 

[Bob in Calif.]

Re: I hate it when this happens!

LubeDude..........<br /><br />You should have driven it down to Needles, Ca. on Wednesday, for a REAL test. It was 117F there.<br /><br /> ...Bob in Calif...

 

[LubeDude]

Re: I hate it when this happens!

Oh yes, Needles, I have been there in the summer too, I try and stay away from that place as much as posible.

 

[roscoe]

Re: I hate it when this happens!

My Blazer did the same thing, right after new belt and hoses, flush n fill. It would fluctuate but ran at about the correct temp around town. Took it out on the highway and the fluctuation was worse and it would occasionally spike like steam was hitting the sending unit.<br /><br />Apparently there was an air pocket in the heater core that did not work its way out when we filled it. It didn't work its way out till it was out on the highway. It sucked the reservoir dry and still needed more.<br /><br />Temp gauge rides steady since then.

 

[LubeDude]

Re: I hate it when this happens!

Well, I drained the system today and refilled it just to make sure there was no air pockets. Guess what, It still does the same thing. Never overheats. I guess I will see if it settles out on the trip this week.

 

[ZmOz]

Re: I hate it when this happens!

Did you use Amsoil antifreeze?

 

[kenimpzoom]

Re: I hate it when this happens!

See if you can clip and ohmeter on the temp sending unit and see if the sending unit is actually changing, or is it the gauge.<br /><br />Can you easily pull the sending unit out, perhaps some crud got stuck in the mounting hole.<br /><br />Ken

 

[dolluper]

Re: I hate it when this happens!

A 190 stat seems a little high espically when towing your sort of defeating the gain of the 2 core rad,a 160 would make her run real cool,so I would at least lower it from 190 what ever you can get around 170-180

 

[Realgun]

Re: I hate it when this happens!

A 190 stat seems a little high espically when towing your sort of defeating the gain of the 2 core rad,a 160 would make her run real cool,so I would at least lower it from 190 what ever you can get around 170-180

No then your milage sucks. This is due to the computer thinking you just need to get warmer. Stick with the correct tempurature T-Stat so the computer can do it job.

 

[ZmOz]

Re: I hate it when this happens!

Originally posted by Realgun:<br />Stick with the correct tempurature T-Stat so the computer can do it job.

Exactly. This goes for ALL computer controlled vehicles. A lower t-stat will not lower your operating temperature unless you have a very good cooling system and you're already running at stat temperature. (most are not)