What temp should 1.6 TD be at?

[86jetta1.6]

I just picked up another Jetta. This time a '86 TD. Seems to run GREAT. I bought it unrunning, having sat in a barn for 2 years untouched, some lubricant in the cylinders and it fired up and drove home 200 miles. Only issue i had was it threw the belts in the first ten minutes but i noticed it immediately and pulled off and put new ones on, i had spares me and was back en route home 10 min later.

The ISSUE: Red light in temp guage blinks constantly and temp rises to 7/8 of the scale on the high side. I put my infared thermometer on it and most of engine is 60 degrees with a very small area right on right side of engine by what I assume is the coolant exit from the engine at 204 degrees. Everywhere else seems to be around 160. I am thinking the guage is off since i looked up the t-stat and there is a 180 and 195 degree options. 204 degrees seems slightly high but i don't think it should almost max out the scale. Touching the radiator hoses they are hot but I can still grab them for a second. I really dont think this is overheating as extreme as the guage shows. Any thoughts?

I searched past threads and saw a lot of mention of checking the grounds, I will do that this morning.

[TylerDurden]

Might be a bit hot, but best to check the sender first.

Unplug the sender wire and see if the gauge drops, ground the wire and see if the gauge pegs. If so, the wiring is ok and the sender needs testing.

I tested a sender from an 89, but I rekon the values should be similar for the 86 sender.

[82vdub]

I don't think 204 is too high. You may want to verify that you have coolant coming out of the small line to the radiator fill jug, and that you have a good clean radiator in it. Your gauge or the temp sensor may be goofy too, or that you have a bad ground as well.

[86jetta1.6]

No coolate coming out of upper tube in resevoir, does that mean bad water pump?
If i rev the engine up I get a small splash of coolant to come out but only for a split second. Water pump or t-stat? If the t-stat is closed will coolant still come out of that small tube?

[TylerDurden]

That tube should piss constantly: weakly at idle, strongly at speed; regardless of t-stat opening. Spurts are air purging out. Top off the tank to the fill-line as the air purges.

If it is spurting, the tube is probably not plugged (plugged is bad).

I'd flush system and replace tstat if you haven't already.

[82vdub]

I agree with TylerDurden. It should have a flow of coolant consistantly. If no flow through this line, then there's no removal of air from the system, unless air burps from the return hose at the bottom of the tank. You could have a bad water pump, or a water pump where the impeller isn't properly spinning on it's shaft (some have discovered this issue). But, investigate why coolant isn't properly circulating through the whole system. I've found that sometimes the little barb in the radiator is plugged, and some of the lines have a restrictor orifice towards the jug end of the line (feel for a hard lump in the line). Most typically remove that orifice device. I've had that orifice plug up with a piece of pine needle, and just junk in the coolant system plug up the hose barb in the radiator.

[86jetta1.6]

I bought a 180 degree t-stat. I will change that this afternoon although you just said t-stat shouldnt affect the stream coming out of the line. Just to make sure i am clear, there is NO Coolant coming into resevoir, when i rev the engine I get about 1/4 of a teaspoon to come out. then it stops again. I am assuming becuase of that the tube isnt plugged. Either something is clogged or waterpump is not pumping i assume.

[86jetta1.6]

I will try and investigate now. Heading out to the garage

[82vdub]

I am assuming becuase of that the tube isnt plugged. Either something is clogged or waterpump is not pumping i assume.

I wouldn't assume it's ok. Higher engine RPM will result in more coolant flow, and possibly result in fluid being pushed past a partial clog. It's really easy to check for a blockage at the barb on the radiator and for the orifice in the line. Can you blow air though that line? It's a small line, so it's possible that the rubber deteriorated too. Just throwing out ideas, but this is an easy check.

[86jetta1.6]

I'll go check now, I appreciate the ideas, thanks!

[86jetta1.6]

I agree with TylerDurden. It should have a flow of coolant consistantly. If no flow through this line, then there's no removal of air from the system, unless air burps from the return hose at the bottom of the tank. You could have a bad water pump, or a water pump where the impeller isn't properly spinning on it's shaft (some have discovered this issue). But, investigate why coolant isn't properly circulating through the whole system. I've found that sometimes the little barb in the radiator is plugged, and some of the lines have a restrictor orifice towards the jug end of the line (feel for a hard lump in the line). Most typically remove that orifice device. I've had that orifice plug up with a piece of pine needle, and just junk in the coolant system plug up the hose barb in the radiator.

I felt the line going to top of resevoir, no orifice found. When I squeeze the upper radiator hose i get coolant going into the resevoir from the the bottom hose, not the top tube. I removed the hose from the resevoir and tried to blow back towards the upper radiator hose but could not blow through it.

[86jetta1.6]

Took off the upper radiator hose, blew threw small line going to resevoir, very restricted, blew a lot of ait through it, still restricted. Replaced with one off of parts car, I now have a steady stream! Much better than replacing the water pump, I took a look at the water pump, and it looks clean and new! I wonder if the previous owner was having issues as well. Haven't test drove it yet. Will shortly! Thanks guys

[82vdub]

Glad you figured it out. From previous experience, pay attention to that water flow as you get used to the car, because you blew what was plugging the little hose back into the coolant system. It may block that passage again, and it may not. I got tired of messing with it on Ole 82, so I just replaced the radiator with a new one (it was getting time anyways), so it's good to go for another couple hundred thousand miles.

That little hose and that radiator fill jug is a key point for analyzing or determining how your coolant system is functioning. If your lower hose is burping air into the jug, it's not flowing coolant like it should, et al.

[brifrompa]

just got on to check out this same ordeal ,here it is at the top of the page! Mine is an 81,the lil truck .I also have a 4-door LS. The caddy overheated the other day,blowed the plastic union connector on the heater hose on my way to work [I-80] . I got pulled off the side ,assessed the situation,and magivered the end of my spout off of my 2 gall. fuel jug.Topped off the anti freeze and made it to work with time to spare,though just as I got parked,that piece of yellow spout/magiver union melted and caused a steam cloud that covered half the parking lot. Anyhow,I have the same problem with nothing coming out of the small hose from the top of the (NEW) radiator to the tank. I took the hose off at the radiator and it is not plugged. [remove cap from tank before blowing on this hose,unless you like the taste of coolant] . I did not know about any of the "restrictors" spoken of here but I will check this out in the morning. The impeller is tight on the shaft,and unless the seal is bad and leaking, I cannot see any logical reason to replace the pump. I did that on my LS, only to find out it was just another crap thermostat. third one did the trick. What is it with getting a thermostat to work in these things?? Also on the 3rd one in the caddy. I drilled 2 3/16 holes in the last one and had no problems all winter,till this episode. My LS circulates as mentioned,but the caddy does not ,maybe just a spurt after idling down after revving it up. Has to be a restriction somewhere ? right??

Brian thanks

[82vdub]

So you removed the small hose at the radiator and blew through it? What about blowing air through the hose the other way and into the radiator to make sure there's nothing plugging the whole line into the radiator?