Author Topic: Overheating (Read 6134 times)

dirkbalter · « **Reply #25 on:** July 17, 2023, 17:17:00 »

Rodd,
I like the summary of yours as a trouble shouting guide. (Would be good for our manual)

Not sure of you last point though.
- Install a "long water pump" if engine currently has a short water pump.
What's the advantage of a long pump with respect to cooling?

Brennie · « **Reply #26 on:** July 17, 2023, 17:17:37 »

Seems only whilst driving… I’ve never let it run long enough to test the theory.. should I?
Sounds like it makes sense.. as I’ve said,it’s done it since the day I bought the car.. I was with a host ( is there a collective noun for a lots of Pagodas?)of Pagodas the other day and not one of them experienced any thing like it.. needle rose to the middle and stayed… mine rises rapidly in and congestion..

rwmastel · « **Reply #27 on:** July 18, 2023, 12:33:27 »

Quote from: dirkbalter on July 17, 2023, 17:17:00

Not sure of you last point though.
- Install a "long water pump" if engine currently has a short water pump.
What's the advantage of a long pump with respect to cooling?

I believe on a 230SL it will put the fan closer to the back of the radiator, creating a better draw of air through the radiator. The "long" part of the pump is on the outside where the fan mounts. I assumed it was on the inside and pumped water differently, and you know what happens when we assume!

dirkbalter · « **Reply #28 on:** July 18, 2023, 15:01:07 »

Rodd,
The water pump for a 230 is unique due to the fact that is is a 3 bolt (fan) mount. Length wise it is in-between the short and long type (4 bolt) water pumps. Together with a solid spacer, the fan bolts directly to the pump.
The 250 and some 280s used a short water (4 bolt) pump, also with a spacer to achieve the fan distance to the radiator.
The 280Sl / SE and some others used a long water pump without spacer.
Except for the 230s, a viscous coupling was installed between the fan and the pump.
The 250-280 fans are slightly bigger than the 230 fan.
They are all interchangeable with respect to mounting to the engine.
However, if you change the 230 to a viscous style pump and fan, you have to trim the fan blades as they will touch or interfere with the air cleaner shroud.

(Hope I didn't miss anything)

I don't know why the short, spacer pump was used instead of the later long ones but don't think there is a cooling advantage within the different pumps.

rwmastel · « **Reply #29 on:** July 18, 2023, 15:20:19 »

Quote from: Brennie on July 17, 2023, 17:17:37

I was with a host (is there a collective noun for a lots of Pagodas?) of Pagodas the other day and ....

OK, that's a great thought. I'm starting a new thread to see who can come up with the best name for a group, host, flock, school, brood, pod, etc. of Pagodas!

https://www.sl113.org/forums/index.php?topic=36907.0

Brennie · « **Reply #30 on:** July 18, 2023, 16:07:22 »

I did ask earlier I think but..
Can you fit a six or nine blade fan directly onto an early 230 SL ( mine) or is that not possible without swapping to a viscous pump…
And, would it make much difference?

rwmastel · « **Reply #31 on:** July 18, 2023, 16:50:05 »

Dirk said those fans with more blades from the 250/280 engines have a larger diameter and can interfere with components on a 230. You would need to find a way to trim the ends of the blades back a bit, and keep it well balanced. I'm not sure if a viscous clutch would be required to be added, or if you could use a spacer/adapter of some kind. Dirk can probably help with that.

dirkbalter · « **Reply #32 on:** July 18, 2023, 18:01:58 »

Quote from: Brennie on July 18, 2023, 16:07:22

I did ask earlier I think but..
Can you fit a six or nine blade fan directly onto an early 230 SL ( mine) or is that not possible without swapping to a viscous pump…
And, would it make much difference?

The multiblade fans that I see at our vendors are all to be mounted to a viscous clutch. However, there are multi blade fans (more than 4) out there from different models or special order options that supposedly fit to a 230 pump direct. You will have to search for these.
I have a long (4 bolt) water pump with clutch and fan installed. I believe I trimmed about 1/2" off the wings.
I drove about 40 miles this morning in 95 degrees temp with a lot of stop and go. No issues, 80-85 C all the way.

(Picture shows a 3 bolt fan and is form the German group. Some of the Unimog's are supposed to have multiblade aluminum fans as well)

ja17 · « **Reply #33 on:** July 20, 2023, 04:14:14 »

Water pump length should not make a difference, since both are spaced the same distance from the radiator. Internal vanes of the pump are identical also. The long pump is easiest to install and should have less load on the bearings in the pump. As mentioned, if the engine still overheats when the car is cruising down the highway 60mph, then most likely it is a defective radiator.

captainslow · « **Reply #34 on:** July 30, 2023, 04:15:11 »

I put a viscous clutch on my 230 so I didn’t have to listen to it at speed, but got to keep the horsepower of a mechanical fan. I used a bmw fan that worked out to be 420mm in diameter. 10/10 would do again. I’ve been driving around on 90+ degree days in slow city traffic in the west hills of PDX and haven’t seen anything above 85 C either. I made a small adapter plate to convert to the bmw bolt pattern. Somewhere online like send cut send or elsewhere could probably set you up with any flat pattern you can draw up.

URO000616 Is the Uro part number for the fan I used, 16 bucks on rockauto. I don’t agree with trimming a non symmetrical fan like the 7 blade off the 280, too much risk for me without being able to dynamically balance but your mileage may vary. Dirk’s trim appears to be successful. The 7 blade fan is also available on rockauto.

I went custom on everything forward of the water pump to make mine work but I’m very happy with it.

mazmonza · « **Reply #35 on:** August 02, 2023, 16:40:11 »

I don't know if it helps but this 9blade fan works for me.

rwmastel · « **Reply #36 on:** August 02, 2023, 17:04:01 »

Quote from: ja17 on July 20, 2023, 04:14:14

Water pump length should not make a difference, since both are spaced the same distance from the radiator.

Joe, or anyone,

I understood from previous posts that the pumps are called long and short because of the distance they extend away from the engine. Is that correct? If it is correct, then they would have to be placing the fan at different distances from the radiator. Please help fill my gap (ha ha) in understanding.

captainslow · « **Reply #37 on:** August 05, 2023, 04:46:52 »

The fan placement should end up roughly if not exactly the same (short to long). The tricky part is that if you take the pulley off a short water pump there is a spacer hiding there to place it out at the correct distance, aka the same distance as the long pulley. The spacer for the 230 was on the forward side of the pulley sandwiched between it and the fan. As far as I can tell all the 4 bolt water pump pulleys are the same depth and the 3 bolt water pump pulley is the same depth but with 3 bolts.

For my 230 I used a short water pump and turned my own pulley. The purpose of this was so I could swap my spacer to the front side of the pulley so I could easily play around with different distances to the radiator or change to a more durable fan clutch in the future. Currently my fan is placed in the exact position as a regular 230 but with a 280 clutch from Uro up front. The 250/280 9 blade plastic fan will not fit on a 230 without trimming. The original 230 4 blade fan is a smaller diameter than the later 9 blade fan, 430 vs 460mm.

cfm65@me.com · « **Reply #38 on:** August 05, 2023, 08:07:13 »

Brennie,
I have noticed your interest in a viscus fan. Unfortunately, this thread has morphed into a long or short fan discussion.

The viscus fan has a clutch, which operates on varying temperatures. When cold the clutch will disengage and the fan will be free to windmill or even stop.
As silicon fluid in the hub heats up, the clutch will engage and the fan will start rotating.
Therefor, when you start a cold engine the fan might or might not turn because the clutch is released. As temperature in the clutch rise, it will engage. At higher speeds when the airflow would be enough the cool the radiator, the viscus clutch, would disengage and again, the fan will be wind milling or might even stop.
The viscus fan is designed to disengage when cold or sufficient airflow cooling is at hand in order to reduce fuel consumption as well as fan noise.
Regards
Chris

Brennie · « **Reply #39 on:** September 09, 2023, 12:27:49 »

Thank you Chris….a perfect description of what and why a viscous fan is….
As my car being a 230 SL,it is without a viscous fan clutch…
I have just had the radiator recored…I’ve been told that the work done on it by the PO was Micky Mouse to sat the least…now it looks great but…didn’t seem to solve the problem…a little bit of traffic on a hot day this week resulted in a massive temperature rise …see picture…
In now thinking a fan fitted on the front of the radiator is the next step…what I’ve asked an still don’t have a definitive answer is …what size fan? and should it blow onto the radiator or suck away from it…and is a SPAL fan the way to go?

BobH · « **Reply #40 on:** September 09, 2023, 13:02:14 »

Hello Brennie, what i don't understand is that there are hundreds of 230's around the world, probably thousands, that have original fans etc, that don't suffer overheating, many in warmer climates than ours in the UK, including my car. I do mainly short journeys, and even with the temperatures we've experienced this past week, i've had no problems

Rodd made some good suggestions, but you don't say if you've investigated and eliminated all of these, particularly the thermostat and timing

Rodd's to do list:

It seems that to get a cooling system into a healthy baseline state one should:
- Pressure test the coolant system
- Chemical descale the coolant system
- Check effectiveness of water pump (not sure how)
- Check effectiveness of fan viscous coupling (if so equipped) (Not applicable)
- Check effectiveness of thermostat (in a pot on the stove, with thermometer)
- Check effectiveness of radiator (thermo imaging looking for cool spots)
- Ensure car is not running lean
-- fix anything found faulty in above tests

Plus check and adjust the timing if required

I'm a believer in fixing the route cause, rather than changing or adding equipment to get around a problem, as it may come back to bite you

Have a read on here, particularly the last few paragraphs

https://www.sl113.org/wiki/Cooling/CoolingSystem

Brennie · « **Reply #41 on:** September 09, 2023, 15:40:32 »

Hi Chris
I just got the car back from the very reputable mechanics who organised the radiator recore ..Wouldn’t they have checked those?
And, which thermostat? Is there more than one?
Is it the one housed in here? I’ve just replaced this thermostat housing by the way.. another PO bodge up…

Brennie · « **Reply #42 on:** September 09, 2023, 15:44:41 »

Ps
And,yes .. the suggestions are very clear and precise… beyond my capabilities most of them..
I wonder if you can add a chemical cleaner to the coolant & water mix without having to flush the whole system?

BobH · « **Reply #43 on:** September 09, 2023, 15:58:10 »

Quote from: Brennie on September 09, 2023, 15:40:32

Hi Chris
I just got the car back from the very reputable mechanics who organised the radiator recore ..Wouldn’t they have checked those?
And, which thermostat? Is there more than one?
Is it the one housed in here? I’ve just replaced this thermostat housing by the way.. another PO bodge up…

That's the warm running device thermostat on the injection pump. There are pictures of the cooling system thermostat housing on this link, different types for the different cars

https://www.sl113.org/forums/index.php?topic=28381.msg205038#msg205038

rwmastel · « **Reply #44 on:** September 10, 2023, 02:56:09 »

Quote from: Brennie on September 09, 2023, 15:40:32

Wouldn’t they have checked those?

If specifically instructed to do so. We're they listed as line item work on the invoice/receipt?

Brennie · « **Reply #45 on:** September 10, 2023, 07:53:22 »

Hi Rodd
No.. but,the reason for taking the car in in the first place was to get the overheating problem sorted out..
I sure there are plenty of discussions here on how to check that thermostat..
Is it an easy job or would I have to replace gaskets etc if I started to fiddle with it?

Jordan · « **Reply #46 on:** September 10, 2023, 10:07:00 »

Brennie, have you actually checked the temperature of various parts of your engine and radiator with an infrared temperature gun? You should find one at your local hardware store for around the equivalent of $20-25. Maybe it is your temperature gauge that is faulty. Get a gun, run the temp up as you have done in the past and then start targeting different parts of the engine and rad, rad hoses etc to see what the actual temps are. Look for both hot and cold spots and then let us know what you find.

When you had your rad recored, did you get a double or triple core?

Brennie · « **Reply #47 on:** September 10, 2023, 12:10:53 »

Mmmmm! Not sure about the recore.. I’m thinking 3… they people who did it ( Viking Radiators Uxbridge) said that the last person to fiddle with it didn’t have a clue what they were doing.. it was a mess apparently… we hoped that the recore would solve the problems.. as soon as traffic clears the temperature drop instantly…
Looking at the thermostat housing by the radiator.. it looks difficult to get at because of the fuel lines( which I’ve also just replaced).. how do I test it without taking the cover off..
Going to look for a heat imaging thingy now..
what am I looking for exactly.. ?

Jordan · « **Reply #48 on:** September 10, 2023, 13:01:56 »

Brennie, just do a search for "infrared temperature gun". Here are some on Amazon.ca https://www.amazon.ca/s?k=infrared+temperature+guns&hvadid=588600920823&hvdev=c&hvlocphy=9000774&hvnetw=g&hvqmt=e&hvrand=8457733683496929432&hvtargid=kwd-304777294294&hydadcr=21265_13338218&tag=googcana-20&ref=pd_sl_7go3d52yye_e. The UK site should have them as well as your local auto parts store.

Make sure you check temps at top, bottom and both sides of rad. Also engine front and back, up and down and the coolant hoses (going into rad and coming out, and coolant hoses on the side of the engine. This will give you a good picture of where the cooler vs hotter spots are. Years ago when I bought an older Dodge pickup I found the temp gauge showed it running quite hot so I used the temperature gun which showed me the engine was not hot at all. It was a faulty gauge.

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Author Topic: Overheating (Read 6134 times)