#11
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I use an infrared thermometer for checking temps in different parts of the engine. They're not hard to find these days. This engine is the only one I've ever seen that circulates the coolant "backwards", i.e. the water comes out the top and returns through the thermostat at the bottom. I wonder why they did that... The system should bleed itself by letting air out of the top of the radiator into the top of the surge tank. You just have to fill it up and then recheck it after running several times.
Regards, Chuck Yarter |
#12
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I've been using an infrared thermometer to check the temps of the head and thermostat housing. I replaced the blown head gasket over Thanksgiving break. Thanks for the information v8volvo, its great to know I'm not alone with these issues.
I think that the culprit is most likely the radiator. The previous owner said that he had it rebuilt by a shop near him. I will begin searching junkyards for a replacement radiator since a new one is approximately $300. |
#13
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I decided to try a 170 degree thermostat. Now it works perfectly! Praise the Lord.
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#14
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The volvos I'm familiar with (most all through '88) have a buffer circuit in the instrument panel that keeps the temp gauge from actually following the temperature as long as it's in the normal range. Seems some drivers get nervous if they see the needle move too fast. IPD sells a replacement for the (plug-in) card that makes the gauge follow the actual temperature. The same thing can be achieved by soldering a jumper wire on the buffer card.
This may account for different operation of temp gages on different cars, if someone has wired out the buffer. The D24 cooling system is different from any I have seen before, and I've been a professional mechanic for 50 years, on both diesel and gas equipment. The coolant enters the engine through the thermostat and leaves through the upper hose. Still, I haven't noticed any issues in the way it works (till it blew the bottom hose and cracked the head before I noticed overheating). |
#15
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Temp Gauge accuracy
Quote:
So, how do you jumper the buffer card? Or, what is a part number for the IPD replacement card? (I couldn't find it on the IPD site.)
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J.D. in Reno 1958 Mercedes 180D (rebuilding now) 1985 VW Jetta 1.6TD 1985 Volvo 745 Wagon 2.4TD (sold but still maintain it) 1987 VW Quantum Syncro 2.2 (converting to 2.0TD) 1996 TDI Passat 1997 Chevy 3/4 ton 6.5TD 2006 V10 TDI Touareg |
#16
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Personal experience: Swapping instrument panels from different 740 TDs gave different temp gauge behavior. Some stayed near halfway point after warmup, others varied more when climbing hills for example. Same engine, same car, so there is some variation in gauge reaction. IMHO, for serious temp. monitoring, get an aftermarket sensor/gauge, preferably digital. Factory equipment can be notoriously inaccurate, most likely to avoid complaints from the new purchaser of the vehicle. The temp gauge sensor is at the front left side of the head, near the #1 GP.
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1985 744 gle d24t 1985 745 gle d24t |
#17
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The great thing about this forum is when you ask the right question you get an answer from someone who has experience. I value that experience!! Is there a way to donate to the forum?
I'll get an aftermarket gauge. I already rebuilt the entire engine bay wiring harness so I know the wiring is sound. I might replace the sensor just to test it.
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J.D. in Reno 1958 Mercedes 180D (rebuilding now) 1985 VW Jetta 1.6TD 1985 Volvo 745 Wagon 2.4TD (sold but still maintain it) 1987 VW Quantum Syncro 2.2 (converting to 2.0TD) 1996 TDI Passat 1997 Chevy 3/4 ton 6.5TD 2006 V10 TDI Touareg |
#18
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Here is the story when i walked this trail.
http://forums.turbobricks.com/showthread.php?t=141850 I have a big dead spot from 175-220ish. |
#19
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Thanks for the link. There's a lot of useful data there, not just opinions but actual facts.
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J.D. in Reno 1958 Mercedes 180D (rebuilding now) 1985 VW Jetta 1.6TD 1985 Volvo 745 Wagon 2.4TD (sold but still maintain it) 1987 VW Quantum Syncro 2.2 (converting to 2.0TD) 1996 TDI Passat 1997 Chevy 3/4 ton 6.5TD 2006 V10 TDI Touareg |
#20
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Does it get too hot or just run hot? Since the heat range rests in the prevent, that part should get hot first, thus starting at the appropriate heat range.
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