Engine temp question

[diesel_lv]

I've got a '87 K5, 350 tbi w 700r transmission. Number reading factory temp gauge. It has a 2 wire, oval plug, temp sending unit next to thermostat housing. It has a single wire sending unit on driver side head between 1st two cylinders. Double wire is for computer and single wire is for gauge. I have large 2-1/4" deep 2 row aluminum radiator, heavy duty fan clutch and new 5 blade factory fan with 195° a/c delco themostat. While driving at 60, temps get up to 230 on gauge. I pull over, take out my lazer heat gun and at thermostat 180°, at 2 wire sensor the same, at 1 wire on side of head 230°. Oil tank shows 180 also. Is it normal for the single wire sensor to get that hot? Or is that sensor put in the wrong location. This is in Fort Mohave, AZ on 108° day. It's May and we are just getting started. See up to 130° air temps here.

 

[bucket]

That's the normal location. Your temp gun was picking up exhaust heat as well.

Likely the sender is slightly out of calibration or the gauge reads a little high. Yes, it does tend to be a little hotter in that location, but not by a lot. 190-200 would be a normal reading there.

 

[diesel_lv]

That's the normal location. Your temp gun was picking up exhaust heat as well.

Likely the sender is slightly out of calibration or the gauge reads a little high. Yes, it does tend to be a little hotter in that location, but not by a lot. 190-200 would be a normal reading there.

So as long as my temp at the thermostat, oil pan and radiator are all within limits I'm good? I'll try to get an ACDelco 1 wire sending unit to hopefully get a better reading on the gauge so I'm not constantly having to get out n check.

 

[C10MixMaster]

I've got a '87 K5, 350 tbi w 700r transmission. Number reading factory temp gauge. It has a 2 wire, oval plug, temp sending unit next to thermostat housing. It has a single wire sending unit on driver side head between 1st two cylinders. Double wire is for computer and single wire is for gauge. I have large 2-1/4" deep 2 row aluminum radiator, heavy duty fan clutch and new 5 blade factory fan with 195° a/c delco themostat. While driving at 60, temps get up to 230 on gauge. I pull over, take out my lazer heat gun and at thermostat 180°, at 2 wire sensor the same, at 1 wire on side of head 230°. Oil tank shows 180 also. Is it normal for the single wire sensor to get that hot? Or is that sensor put in the wrong location. This is in Fort Mohave, AZ on 108° day. It's May and we are just getting started. See up to 130° air temps here.

230 is a little hard on the heads. with an 87 i assume you have a reverse rotation fan serpentine setup. I would consider swapping to a fan from one of the vortec motor , they had 10 or 11 blades as i recall. need all the cooling you can get here in AZ

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[diesel_lv]

No, it's factory V-belt standard rotation.

 

[C10MixMaster]

No, it's factory V-belt standard rotation.

then i would use the 7 blade version

 

[diesel_lv]

then i would use the 7 blade version

If I could find a factory one, I would. The fan only makes a difference at slow speeds, idle and under heavy load. If the thermostat housing, upper sending unit, radiator, oil pan all say 180, then all is good. It's most likely hear soak from being by the exhaust ports on the heads that's causing the temp gauge sending unit to be so hot. The only reason I'd run a 7 blade is for a/c at idle.

 

[diesel_lv]

All figured out. Upper radiator hose was much higher than radiator fill. Kept getting air bubbles after I had put in new radiator, fan clutch and fan. Cut upper hose and so it is below the radiator fill. Now temp using lazer are good at the sending unit on side of head. Gauge still reads 210 now but does not fluctuate. Temps on gun are 180 at all locations. Probably a bad sending unit. But everything is steady and equal temps.

I have a long 454 radiator out of a '89 1 ton. Going to take it and see if a radiator shop can shorten the core to the small block length. It is a 2 row aluminum with transmission cooler and engine oil cooler built in. It is also 17" tall core not 19" tall so everything would bolt in perfect.