1983 D24T running warm
 

Hi all, I have a 1983 760 Turbo Diesel that seems to be running warm at the moment.

I first bought it in January of this year and drove it 1100k's home. For a car that hadn't been started nor driven in 10 years it could not of ran better, apart from it liking to get warm - which was indicated via the temp gauge. The running hot when I first got it probably didn't good more than bad as it allowed the engine to blow out a lot of crap for sitting for 10 years, and god did it. From a gutless smoking freight train to a non smoking peppier sedan it loved the drive home.

I inspected some of the cooling system when I got home. The metal radiator was 3/4 blocked and that's all re-conditioned and installed back in the car. The car had no thermostat, and it still circulated as all the hoses and water in the expansion tank got warm. However, it now has a 90 degree thermostat and re-conditioned radiator but the reading on the temp gauge still climbs to what it was when I first drove it which is just over 3/4 high. The water doesn't seem to be circulating as when the temp gauge reads high, the bottom radiator hose and the expansion tank water are both vaguely warm/cold. Water pump condition is unknown, temp sensor condition is unknown.

What also confuses me is when I turn it off and leave it for a minute, and then start it back up the gauge reads just under half, and then when I start driving it around it goes back up.

Has anyone had any problems like this? Any help is appreciated. Thanks

Were you able to take temperature readings as suggested in this your post?

Make sure you installed the correct thermostat type. Should have the bypass blocking plate like this one:
Attachment 1154

Otherwise too much coolant will just recycle thru the engine and never make it to/from the radiator. Same problem with running this engine with no thermostat. Overheat.

The bypass design is supposed to equalize engine temps (hot spots) and allow early heater before engine reaching operating temps.

Hi, not yet however I did find that the 90 degree thermostat that was installed was faulty and was not opening. I removed that and took it for a drive and all hoses got hot and were same temp, which eliminates the water pump is a good sign, but the needle on the temp gauge stayed cold, on the C. Didn't even climb when the hoses were warm. Faulty temp sensor?

If the temp gauge stopped working at the same time that you replaced the tstat, possible there is an air pocket in the system. Good idea to make sure all air is bled out since this will also cause overheat if the pocket is large. Another possibility is that the wire got pulled off the gauge sender (at front of cylinder head just ahead of #1 glow plug) if the wiring harness that runs near the tstat housing got moved during the work.

90 degree tstat would be a little warmer than stock, 87C is the OE temp. 3C might be enough to make a visible difference on the gauge, these are quite sensitive. If the car had no thermostat installed when you got it, that's a clue that the warm running you are noticing was going on for a previous owner too. The plugged radiator could have been a cause, good that you found that and fixed it.

I would start by checking the electrical connections to the temp gauge sender and making sure the cooling system is well burped, then see what happens. First of all you need the gauge to work. If all the wiring appears OK, you can test the circuit and the gauge by grounding the connector for the sender. The gauge should read full hot with this wire grounded. If it does but you still get no reading when it is connected to the sender, then the sender is the issue (rare). If you get no reading when the wire is grounded, then the issue is with the gauge/cluster (rare) or a wiring connection somewhere between the engine and the dash (common). If you get to this point with no clear answers, reply back here and we can give some tips on further steps.

One factor with your 1983 model is that your temperature gauge shows variations in temperature around the operating set point. 700 series Volvos from late 1984 onward introduced "damped" dummy-style temperature gauges where the needle stays right in the middle for any temperature relatively close to operating temp, roughly 180F-210F. With those later gauges, the only time you see it move up is after a problem is already happening, so the early warning an accurate gauge provides is lost. On your gauge you will see minor fluctuations that are normal. An extra few degrees of operating temp might be visible with a hot thermostat, which the later style gauge would hide.

A few of us have had success running slightly cooler thermostats for improving temperature control in hot weather. If other checks don't turn up obvious problems this could be something to try.

As others suggested - if the car sat 10 years be sure to replace the timing belt. :cool:

Thank You. BIG HELP. I took out the thermostat and let it idle when filling it back up with water, however when taking it for a drive the needle did not rise from cold. All hoses were hot, which is fortunate as the bottom hose was not with the thermostat was in it. The thermostat was also faulty, time for a 80 degree one. Do you know where I can buy a genuine one or any other brands that you would reccomend?

Also I will replace the timing kit, but new to the whole D24 thing, not sure to get one of those either. I am going to get a new temp sensor as it may be covered in gunk from sitting for those 10 years. Then top it all off with silicon hoses.

Also what are some signs the timing belt needs to be replaced. It starts turn of the key every time, and it does not smoke on idle and runs very smooth. Thanks

Sorry, I forgot to add the heater has been bypassed. Why? I don't know, was done by previous owner as it was a farm car and since he's 92 and in a rest home I didn't get to meet him as the car was sold on behalf.

Only sign is the engine will suddenly quit running. Upon further inspection you will find at least bent valves, damaged pistons, probably bent connecting rods as this is an interference engine. Therefore the 65,000 mile timing belt change spec. Note that if it has sat several years in the same position that can cause a "set" in the belt that may result in a premature (in miles, not chronological) failure. So if you don't know the history of the Timing belt, better change it. Requires special tools and knowledge, sorry no way around that. :( Lots of info on that in this forum if you look for it.

People often do this to temporarily "fix" a leaking heater core. What color and KPa marking does the coolant overflow bottle cap have?

Can you get ones for the narrow hoses on the top of the engine? And the lower radiator hose? I would be interested in these also!

The car got a full service before I picked it up at a local mechanic. After I got it home 1400k's later, I took it to my diesel mechanic. He said it was a very happy and healthy motor. The D24T currently in the car is not the original engine, it's still a 83' D24T motor but it has under 100,000 - he didn't specify k's or miles. I will replace anyway, better safe than sorry. Is it a timing belt or a timing chain? and where can I buy them? Thanks

It was parked for 10years.

!!!

Please dont use it because there is a high risk of damages...if timing belt breaks. There must be a VW guy out there to help (tools, skills, etc)

Any LT trucks made it there in the 80s btw? How about in AUS?

Thermostat should be the 80°C version out there. You have no Winters...:)

That is great news! :D Easy starting, good power, low smoke, quiet smooth idle are all good signs.

The issue with an old timing belt is similar to old tires. The "rubber" compound degrades, cracks, and becomes less pliable. Chunks can separate, etc.


Fiberglass-reinforced belt.

My FLAPS has them (Autozone, P/N 95083), yours might also. Time before that I got a Continental brand [CONTITECH TB083 {#069109119A, 1257223, 3507227} Length: 44.63 (in), 1134.00 (mm); Width: 1.00 (in), 25.00 (mm); Number of Teeth: 119] belt from Rockauto. Not expensive.

Might as well get a valve cover gasket because you will be opening that up. Not sure ATM where to get the one-piece all-rubber ones. If you are going to order from Rockauto, see if you can get them to describe the VC gasket style. Their pictures show the old 4-piece cork north/south + rubber east/west sections that were always leakers, but unless those are real old stock, I had heard that the only ones currently manufactured are the one-piece black "rubber" ones that seal better, so maybe that's what they actually send?

Do you think a block flush would help? Do the D24T's even like an acidic block flush? Just thinking that sitting for 10 years in a farm industrial area, it could help because all off the crap it collected over the years of sitting.

What is the specific problem you are trying to solve with a "block flush?" What is a "block flush?"

I think he means getting rid of all leftover debris by flushing the engine (="block") completely, allowing higher pressures of water entering for a longer period of time then reversing the direction and keep switching between routes of "flushing" through the entire cooling system, including the engibe block itself.
The overheat problem probably runs somewhere else though. I suspect the wrong thermostat too. He has a lot of things to confirm before trusting it.

I heard citric acid works wonders but after ten years of car sitting untouched (AND unknown history of proper maintenance) I would definitely stop experimenting around the cooling system and probably would decide by a full (real full) tune-up... Valves adjusted --- at the minimum, then hoses, top gasket and all you can think of, including getting fresh nozzles, glowplugs, and maybe much more (check and flush and adjust pump, do waterpump, belts and possibly even check wiring).

I hope it turns out to be a great runner!!!
As #1, I dont get it why PO ran it without the thermostat.

Yea, I may give it an engine flush just to eliminate that cause. It sat for 10 years after all. The car runs great, it starts up turn of the key no matter how long it's been sitting. Doesn't get that cold here often in NZ, so that helps. Also it doesn't smoke, you get it on the highway and put your foot down and it responds, the car pulls great.

I would trust it on any journey, just that cooling issue would have to be solved. New hoses will be done, will be getting a set of silicon hoses eventually. I want to replace the cooling system parts so I know it's good, such as waterpump and temperature sensor. Temperature sensor could have a lot of carbon build up around it making it read wrong. Just finding parts is the hard part.

VERY unlikely. Carbon buildup in the cooling system? :confused:

Anyway, easy enough to unscrew it and take a look at the business end of the sensor. Let us know what it looks like.

Changed my mind. Maybe not so easy to remove the temp sensor because of the PS pump bracket obstructs. Easiest step would be to correlate gauge temps with a non-contact infrared thermometer.

I'm curious,
In New Zealand, can you "sometimes" see other diesel Volvos on the road? Are they 240, 740, 760, 940 cars? And did they ever get the 5cyl tdi versions of newer Volvo cars?
Do you have the European vintage LT trucks out there? (Made by VW)...lt28, lt35, lt45 etc those would have the d24&d24t parts you may need.

These diesel Volvos are becoming very rare sight, even in Europe!! And nowdays there are all these bans against all diesel powered vehicles (and against all gasoline powered vehicles too)...all over in Europe, pretty much in all of Europe's countries.

I thought I would ask You how it is going in NZ?!
And I found one article that mentions possible new sanctions in the future in NZ.
https://www.google.com/amp/s/teggtal...-vehicles/amp/
I hope you get your car running great soon and that you find a d24t parts-car soon enough to make sure your d24t powered Volvo will stay on the road (before potential d24 leftovers end up getting scrapped). Do you have d24 240 volvos at least? It must already be a rare sight out there!
Keep bricking! :)

Haha, Thank You Red Arrow.

As far as D24 powered Volvo's in NZ, there are 3. Yep, just 3. My 1983 760 diesel, a 1989 740 auto, and a 90's 940 auto. The 740 is an interesting one. That is now off the road due to being in a crash and the plates are handed in so the car is now offically de-registered on NZ roads. It still exists and I have bought it for $600. However, as it is in the South Island and I am in the North it was stored at the owners farm. Now I just got word that it got hit by a digger numerous times and that it is now folded and filled over with dirt - pictures yet to come, only going on from what I have heard. I will be getting the D24 from it as parts, but I am soon to find out what the condition of the car is. Hopefully it is alright, the front was already a mess from being clipped which caused it to be off the road, but it still ran, just the radiator fan was broken and a few belts had been shoved in and ripped off.

About the VW Lt's that got the D24's, it is highly likely we didn't get them. Maybe someone imported one or two but they were not NZ new. We didn't even get the D24 Volvo's new in NZ. All 3 are imports. We got the Turbo's and GLE's new, which I own - 3 x 1983/4 760 Turbo's, B23ET, M46 manual. and 1x 1984 760 GLE, B28E, AW71. All need a bit of work, but they are all close.

New Zealand is a bit behind in decisions such as removing petrol and diesel cars. Since farms are a big part of the country, we still rely on petrol and diesel cars. I think it will be a while before that decision to go fully electric will be implemented, but I am seeing increased amount of electric cars on the road, but so is most countries.

We've got 5cyl Volvo's. We get most of the Volvo's, but one that has not come to our country is the new V90. We have got the Cross Country version, but not the standard version. No idea why, we've got the batch of S90's.

Thanks, my 83' Turbo Diesel is a rare one, I will keep it on the road and as happy and healthy as possible. That's why I joined this forum, for extra help onto keeping the D24 healthy, as I am new to this scene. It won't be scrapped, I want to keep it on the road and rack up the mileage on it.