Heating up / Overheating under load

[Josh]

So I was on a trip to Seattle yesterday and I was going about 85ish up I-5 on a hill and I looked down and my needle was a little more than 3/4 the way up the temp gauge. I let off the gas and coasted for a while and it started cooling down. Now whenever I'm putting load on the motor above like 60mph the temp gauge starts to climb. What can cause this? Broken clutch fan? Bad coolant? Blocked Radiator? Anyone ever experienced something like this? I have quite a bit more driving to do but it doesn't seem to be doing it if I take it easy on the gas pedal. I'm not really sure what happened... it was working fine before this happened, I'm not exactly nice to the go pedal all the time but its never overheated...

Thanks!

[Jason]

Whats the history of the cooling system? Have you ever flushed it? All kinds of crap can build up in the radiator and in the block that will reduce the systems effectiveness. What about the coolant itself, have you checked the concentration? Is the system holding pressure? Check all those things out.

Jason

[Josh]

system is holding pressure. coolant smells like crap.... not like coolant at all. I haven't flushed it as I've only owned it for a month or so. I'll flush it when I get home. I've been driving it around pretty hard and it hasn't been heating up... but I haven't really hit any major hills at any real speed. I'll report back after I drive 300 miles tomorrow :O

Whats really funny is the car now seems more peppy in town after it heated up some... maybe it blew out a bit of carbon or something from the heat? Hopefully it didn't damage anything though.

[77volvo245]

Make sure your not leaking any coolant

I think my temp guage on my diesel reads incorrect as well. In 5th gear at crusing speed it seems the temp reads above normal. I've replace everything and still not reading right. I have a 92+ 740 N/A radiator with an E-fan as well to cool it down. When I bought the car the body was sitting for about 9 years:o maybe that is why.

[Josh]

Nope the coolant tank stays full! :o Its just really weird! I think there's something blocking flow in the radiator.

[reed]

Dont forget to check pump timing. Or the thermostat.

[Jason]

Pull the top radiator support/header plate that bolts down over the radiator and condenser. There is a gap in there and my car had a bunch of crap in there. The coolant flush and replacement should be first on the list, then hose the radiator out too. With that top plate removed you can get directly at the radiator to clean the coils.

Jason

[Josh]

Will do, once I get home on Tuesday :)

[heavyequipment]

Probably not the fan clutch. That problem shows up worse at low speeds/stuck in traffic. My vote is for a clogged radiator, internally or externally.

Could also be exhaust restriction. The stock mufflers soot up. I removed my resonator and replaced it with pipe. Then I replaced the stock muffler with a straight-through (cherry bomb) muffler. It sounds OK and the boost pressure rises quicker (a lot) when I floor it.

These things use a lot of special hoses in the cooling system. I've replace a lot of the special ones with copper pipe fittings soldered together to get the bends and sizes right.

[Josh]

Well I'm going to search for a clog tomorrow when I get home. If it still does that after I flush the coolant and stuff I'll look at the hoses but I'm thinking its the radiator.

[Jason]

Let us know what you find.

Jason

[v8volvo]

Mine heats up under load too. Is this a turbodiesel or NA? Could be headgasket. How is your heater output?

I agree clogged rad is likely cause. If you are still in Seattle, stop by and we can take a look at it together... I am around. Shoot me a PM if you want a phone number.

[Josh]

Sadly I'm home now. Its a turbodiesel.. I'm really hoping its not the headgasket :(... I don't have the money to do a radiator flush right now but it seems to be running just fine as long as I don't go up any long hills :(. I'll be getting a little money sometime next weekend so we'll see how that goes.

[Slobodan]

Just putting it out there, Could be faulty injector(s).

[Josh]

How might I get that tested Slobodan? I recently had the radiator flushed and it didn't make any difference.. Need to figure this out >_<

[Jason]

Did you replace the T-stat? Is the system holding pressure when the engine is running?

You would need to take the injectors out and get them pop tested and or rebuilt. Obviously if your engine isn't knocking like he was saying they aren't too bad, but it could be making it worse.

Jason

[Josh]

I dunno... the motor is pretty loud... and seems to lose power after the car warms up to operating temps and then starts to heat up under medium-high load. Its starting to sound like that might be the issue. I just wonder where I can take it to have it tested. IPD is located here in portland... they're volvo specialists but since its a diesel, I kinda expect them to have never seen one before.

Also, yes its holding pressure and not eating coolant... haven't checked the thermostat though, I'll replace that sometime soon. I'm moving to Eugene next week so I'm a bit busy :(

[Jason]

Are you a member of the D24 mailing list? You may want to get in contact with Tom Bryant. He can pop test and or rebuild them, and from what I understand he is very reasonable. That is if you cant find anyone close by, he is in Maine. Loosing power when warm is kinda backwards, usually they run better when warm!

Jason

[m-reg]

I think I got clogged exhaust too, on cool mornings it goes like I guess it should then in hot afternoon real slow like you need longer leg to push pedal more, temp gauge stays smack in middle though. First thought needed bigger intercooler or maybe cool air pipr to injector pump, sometimes gets a hissing noise when should be boosting so I think need to do exhaust first. never seen my boost pressure light comeon either, in old days used it as gear change light (when light came on time to change up lol)

[MRDART]

Check your radiator hoses for excessive pressure, because sometimes a blown headgasket doesn´t eat coolant it just pushes compression into it making an air pocket in the system and causing a no flow situation. I´ve seen it on two of my engines....

If you buy a new thermostat there should be a little hole in it to bypass some fluid even when it´s closed, I recomend drilling one more hole on the opposite side(makes it esier to bleed out any air in the system)

Then you might want to replace the radiator, I don´t know how it is in the US but here in sweden they replace cellpackage and reuse your old sides. so you should not have to search to hard for a new radiator.

These engines produce a lot of heat so the standard gasser radiator is not a good choise...

[lalozf]

did you checked the thermostat in the air filter, there is a tap that selects from hot/cold air.
The other day mine began to raise temperature and found that I was getting hot air, I fixed it and now temperature is ok, I leave you a link to some pictures,
http://www.volvo4life.es/foro/index.php?topic=19375.0

[v8volvo]

All D24T Volvos should be modified in this way. It's not good for the engine to have a "hot air intake". On all of mine, I remove the metal flex tube from the header to the airbox and remove the little plate on the header that it connects to (just so that it's not sitting there looking like something is supposed to attach to it). Then I open up the airbox and use a small screw to permanently fix the air diverter door in the bottom of the airbox assy in the "cold" position (I screw it shut on the hot side). On virtually any older Volvo, this system is almost guaranteed to be broken and it always fails in the hot position. This makes for worse performance, more wear and more heat in the engine, which is not what you need if you are trying to diagnose an overheating issue.

Everyone who hasn't checked this on their car should do it! A very easy and important modification...

[lalozf]

do you have any news?
I have now the same problem, today I run the car 10 miles and touched the hoses of coolant, only one was hot, the big one that goes out from the thermostat, the other ones were cold..:confused:
tomorrow i will flush the whole coolant and replace the therostat

[Josh]

My car hasn't done it since I moved to Eugene... probably because if I drive its only in town and not up any hills. I can run it up to 60mph flatout and not have the temp gauge go up... it used to go up if I did that. Its a bit colder out now though and it seems to happen most when it was hot. Its a really weird problem.

[lalozf]

I replaced thermostat and coolant and the problem got worse, the car overheats to the red line.
we let the thermostat opened and tomorrow we will change the pump

[IceV_760]

Old original water pump have only 4 blades, and its same whats used
on 4-cyl diesel. But theres nowadays out waterpumps with 6 blades,
causing higher water flow. I believe tho at you have air in your system somewhere, blocking the water flow. These are real beasts to remove air from system,
often its just plain luck.

By the way, have you car yet overheated really?
Since, these are like one-shot engines, one overheat, and cylinder head is done.

[lalozf]

no it did not overheat, we were testing only.
we tried one hose (the the first out of pump way), we unplgged it and it did not throw water with the car turned on, that´s why we think the pump is dead.
tomorrow we will know, with the new pump.
anyway how could I know if it is only air blocks?
and how could I get rid of them?
thanks

[lalozf]

well, I flushed the coolant 3 times, changed the pump (for one with 5 blades, I had one with 7 blades in the car before) the thermostat, and the car overheats in 2 minutes, I do not have de owners manual, and did not open cold star device (:mad:). I read it today
yesterdat I found the problem I did not have heat,by the blower fan, so I did have air in the circuit, I went through several bumps, touched the coolant hoses and played with hot air selector. and the car asked me for 3 litres of coolant more!!!!, that was the problem.
Now is ok, PROBLEM SOLVED.
thanks

[IceV_760]

Nice to hear you get it work as intented.
These are real shits to air, already worrying tomorrow
when i change my upper water hose.
Makes me probably to lose my nerves atleast once, but well,
its normal with this engine.

[RedArrow]

All D24T Volvos should be modified in this way. It's not good for the engine to have a "hot air intake". On all of mine, I remove the metal flex tube from the header to the airbox and remove the little plate on the header that it connects to (just so that it's not sitting there looking like something is supposed to attach to it). Then I open up the airbox and use a small screw to permanently fix the air diverter door in the bottom of the airbox assy in the "cold" position (I screw it shut on the hot side). On virtually any older Volvo, this system is almost guaranteed to be broken and it always fails in the hot position. This makes for worse performance, more wear and more heat in the engine, which is not what you need if you are trying to diagnose an overheating issue.

Everyone who hasn't checked this on their car should do it! A very easy and important modification...

Let`s bring this important post back.
Thanks v8volvo!
I`ll check mine tomorrow. Almost sure it has been done already.

[ngoma]

I prefer to maintain mine in working condition instead of modifying it to always supply cold air. I think it helps speed warmup times. Don't forget, cold engine operation/extended warmups also accelerate engine wear.

http://www.ipdusa.com/products/5451/103083-airbox-thermostat-valve

[745 TurboGreasel]

Possibly relevant, TIC cars don't have the heat hose.

[RedArrow]

NGOMA: I prefer to maintain mine in working condition instead of modifying it to always supply cold air. I think it helps speed warmup times. Don't forget, cold engine operation/extended warmups also accelerate engine wear.
Yes Sir but I`m afraid I can`t afford taking any risk with this survivor old lady. :) I let it warm up and drive it respectfully, cold or warm. :)

ok,... & the preheat tube is not there either, so i`m ok :0)

[casioqv]

I prefer to maintain mine in working condition instead of modifying it to always supply cold air.

Is that actually possible? When I first got into Volvos I thought I would do this, but could never find an airbox thermostat that would last as long as a month! Maybe it was because I was buying them at 'import parts' places instead of the Volvo dealership.

Anyway, where I live it only gets below 50°F ambient a few days a year, so having it working would be pointless.

[ngoma]

Now I better check mine!

[ngoma]

Looks like it works!

Hot (warm, actually)
523

Cold
524