Topic: leaking injector(s)?

[21Rouge]

Terrible heat as in low heat?

Very low heat.

Some thermos are easy to remove.  Don't know your vehicle. 

I think it is obstructed by the intake manifold? Does that make sense?

[articsteve]

If not you might have a big air lock.

Will that not result in engine overheating instead of under-heating though?

If not you might have a big air lock.  Just a guess.

You never know with some systems.  We first seek a no cost solution no matter how improbable.

I think it is obstructed by the intake manifold? Does that make sense?

Completely.  Some motors were never designed to repair.

Squeeze the upper rad hose.

[barrie1]

It does make sence if this engine is not getting up to proper temp as it will retain extra unused fuel in it. It will possibly run too rich with this happening and giving too much fuel mixture mixing with the oil over a certain time frame. A new 195 stat is cheap to change but if its air then its even cheaper yet to get rid of it.. Your Heater should be turned on to High Fan and heat when doing a bleed on the rad system. You might actually be low on fluid which will give you these problems as well. 

[21Rouge]

You might actually be low on fluid which will give you these problems as well. 

I always take notice of the fill container for the antifreeze. No change in level for the past year ie above full .

[21Rouge]

First how does one easily diagnose a defective tstat?

Only way I know is to remove it.

You mean remove *and* replace it ie you can't tell if the thermostat is defective with a visual inspection of the old tstat or can you?

[barrie1]

A new stat is usually around $10.00 to $15.00 with gasket if required. They are not that bad to replace on most vehicles as well. The only way to test it is to put it into a pot of boiling water and watch the reaction of it. The centre flap should open from the heat. A new 195 degree stat is probably the way to go as if you remove the old one you might as well replace it. That way you know for sure what is in there. After replacement remember to run the engine heater fan on High Heat to make sure all air is out of it. 

[21Rouge]

They are not that bad to replace on most vehicles as well.

Supposedly very much of a pain to replace on this 2000 Pontiac engine ie remove the air cleaner tube, throttle body; and so the thermostat is just below the throttle body in the aluminum cast housing; behind the exhaust cross over tube.

[barrie1]

Sounds like removing the Doghouse will be in order. It would be the same for removing the plugs which is why i wonder if they were done or not. Some mechanics are lazy and say they did the work but didn't because of this reason. 

[articsteve]

DRIVE IT TILL SHE BLOWS

 

[21Rouge]

A new 195 degree stat is probably the way to go as if you remove the old one you might as well replace it. That way you know for sure what is in there.

An update. The dealership confirmed that the engine was running too cool  (only 83 degrees). They recommended replacing the tstat. I decided to give this job to my local mechanic.
I just called him and he did replace it but the original tstat wasnt open as he expected (if it the van was running cold, as it is)  . He has drained and filled as well. But hasnt had time to drive it. I am hoping the temp will rise but I am not convinced given the condition of the original...ie it seemed ok. What do you think? 

[barrie1]

Only on rare occasions will you see any damage to the spring. They can break as i have had that happen a few times in my life but they just lose the tension after opening and closing thousands of times over the years. As long as they get all of the air out of the system it should be fine now. You will know very quickly with the extra heat you should have and a higher temp reading on the gauge on the dash as well. 

[21Rouge]

Only on rare occasions will you see any damage to the spring. They can break as i have had that happen a few times in my life but they just lose the tension after opening and closing thousands of times over the years. As long as they get all of the air out of the system it should be fine now. You will know very quickly with the extra heat you should have and a higher temp reading on the gauge on the dash as well. 

Got back the car. It definitely runs hotter...just not sure if it is hot enough  . Before the temp gauge went to just below (1 small graduation) the quarter mark. Now, driving home, with the fan and heater on high it stabilizes one or two notches above the quarter. And it rises from that when idling. Anyone else have a Montana that I can compare to ?   

[Seafoam]

Only on rare occasions will you see any damage to the spring. They can break as i have had that happen a few times in my life but they just lose the tension after opening and closing thousands of times over the years. As long as they get all of the air out of the system it should be fine now. You will know very quickly with the extra heat you should have and a higher temp reading on the gauge on the dash as well. 

Did your mechanic change the rad cap as well ? A friend of mine had the same vehicle , his cooling system was losing pressure because the rad cap
was defective. His temp guage would vary widely depending on the type of driving he did. I don't know if this will help but rad caps are cheap it may be worth a try.

Andrew
Got back the car. It definitely runs hotter...just not sure if it is hot enough  . Before the temp gauge went to just below (1 small graduation) the quarter mark. Now, driving home, with the fan and heater on high it stabilizes one or two notches above the quarter. And it rises from that when idling. Anyone else have a Montana that I can compare to ?   

[ericthejet]

As you are now running a hotter Tstat you can expect the guage to show a difference.  At a stop you may notice the guage go up a bit prior to the cooling fan(if needed) kicking in.
I think that bad thermostat had added to your issues.  Your feeling on the 3 other plugs seems correct as well.  I have a performance motorcycle and change the plugs twice a season.  The gap does not change any significant amount.  If your engine is running properly the color of the plugs will be the same all around.
I could not help but notice all the work you had done at 108000kms.  I won't mention the brand of car I drive but it still has all the original ign. parts except for the plugs at 185000kms abd runs like a dream.  I check the cap/rotor each spring for carbon and its clean.  I still have my original ignition wires too.

Good luck with your van and don't sweat the small stuff too much.

[barrie1]

You casn drive your vehicle until it is fully warmed up and the gauge seems to be at its highest on the reading. Take a small thermometer and place it partway into your airduct and again have your heater set to High Fan Max Heat. Take a reading as it will be very close to 195' I imagine now. A 195' stat is the recogmended one for this vehicle. I do the same for my Air Conditioning in the summer in the car. I look for around 60' farenheight or a little less on the reading for it. I have a thermomenter that is made for shop use and it looks like one you stick into a Turkey or large chicken when cooking one. 

[21Rouge]

You casn drive your vehicle until it is fully warmed up and the gauge seems to be at its highest on the reading. Take a small thermometer and place it partway into your airduct and again have your heater set to High Fan Max Heat.

Thanks for the tip Barrie. Just to clarify: the thermometer goes into a front air vent on the dash right?

Take a reading as it will be very close to 195'

If the standard temp guage on the Montana's instrument panel is accurate than it would display a reading close to 195 as well right...well actually it would be 90 as I take it the scale on the panel is celcius (it shows range of 70 to 125).

I have a thermomenter that is made for shop use and it looks like one you stick into a Turkey or large chicken when cooking one. 

I will use the one which is now in my bbq

[barrie1]

Yes put it in the Vent in the dash to check it out as I know you haven't really a place in the bottom of it to place it into. I have a feeling that it should run much better now even just being up to a proper operating temp on a full time basis. It will heat up much faster and give you more heat then you had as well. All engines are made to run more efficeintly when operating at a certain temperature.   

[21Rouge]

Yes put it in the Vent in the dash to check it out as I know you haven't really a place in the bottom of it to place it into.

I tried this this morning but the thermometer I use for the bbq must not be sensitive enough as I could only roughly estimate the temp from the heat vent as somewhere between 110 and 130?? as the first defined level on the thermometer was 140...and it was below that. (But just as a test I tried the same with my properly functioning other car and had similar difficulties getting a true temp read.)

I have a feeling that it should run much better now even just being up to a proper operating temp on a full time basis. It will heat up much faster and give you more heat then you had as well. All engines are made to run more efficeintly when operating at a certain temperature. 

I agree with all you say. I just am not convinced that the slight increase in temp as shown by the temp instrument subsequent to the change in tstat and drain and refill of antifreeze has now brought it to "proper operating temp". Before tstat replacement it rose to one graduation below the quarter mark; after the replacement it is one subdivision above the 1/4 mark.....(although with the fan off and engine idling I can get it to rise to almost the half way mark)

[barrie1]

I am not sure the difference in between the readings of Celcius or Farenheit but do know that it has to help any engine run better. Can you stick it in the actual rad when removing the cap. The engine will be quite Hot and you will have to be careful not to get burnt but if this vehicle is equipped with a Rad Cap then you should be able to draw a temp reading direct from there.  We also have to remember Not all gauges are totally 100% accurate either as well. Myself I always change out the gauge and put a set of Auto Meter type gauges under the dash when I can. I find these to be very accurate for the price involved.