Project Mercedes Benz - W123 230E & W124 200E - Both happy and working ok

[Peter C]

On 3/30/2020 at 9:08 PM, GBJ said:

This has probably been covered already, but how do you know it is running cool?

Maybe the sender or gauge are wrong?

Because, when driven at low speeds in an urban environment, the engine temperature gauge indicates that the engine has reached its correct operating temperature and as the gauge reaches approx 90 deg C, the electric fan, which I've set to kick in at 90 deg C, kicks in. 

Yesterday morning I made an essential 35 mile journey along the M40, M25 and back home the same way. On the motorway, the engine temperature reached:

However, once I came off the motorway and drove through town at speeds of less than 30MPH and reached my destination, the engine was operating near enough at its correct temperature.

On route home I pushed the 200E up to 90MPH on a completely clear stretch of the M40. Once I got home and the engine cooled down a bit, I removed the expansion tank cap to find no evidence of any significant mayo build up. Deeper in the tank, the coolant was clean. If I have a cylinder head or head gasket problem, it's not massively serious just yet.

[HMC]

Looking at the rad it’s a standard one too, i had a 200 non air con estate and I  used the part numbers for a larger full depth/ width rad from a car with air con by chopping the alloy feet the smaller rad is sat on and using the matching cowling to the cooling fan. Even that did not over cool the car at speed; despite the aircon spec rad being loads bigger (I think as the air con rad is usually sat in front of the engine rad and obstructs airflow)

[Peter C]

1 hour ago, HMC said:

Looking at the rad it’s a standard one too, i had a 200 non air con estate and I  used the part numbers for a larger full depth/ width rad from a car with air con by chopping the alloy feet the smaller rad is sat on and using the matching cowling to the cooling fan. Even that did not over cool the car at speed; despite the aircon spec rad being loads bigger (I think as the air con rad is usually sat in front of the engine rad and obstructs airflow)

Yep, the rad is stock and nice and clear.

[Zelandeth]

Pretty sure I remember reading somewhere that head gasket failure on these only very rarely allows water into the oil but oil in the water in a more common symptom.  Might be that you do have a slightly leaky gasket causing a tiny amount of oil through but not enough to cause any other issues.

Sadly I don't think there's really any way to conclusively prove it without changing it...so I'd be tempted to just keep an eye on it for now.  Do you know if the head has been off before?  If so it could be residue from a historic issue - it can take ages to get rid of oil residue just using water alone.

Might be worth flushing the system with an appropriate cleaner to try to get rid of it and see if it stays gone.

Do keep an eye on the condition of the coolant hoses though as depending on what type of rubber they're made of the oil can attack them internally and weaken them. 

[Pete-M]

That is definitely running too cool. Most Merc engines run at between 90°-100° or they're not happy. 

Having the electric fan set at 90° won't help as you're cooling the engine just as it reaches operating temperature. I'd set it at 100° ish so it kicks in when things begin to get hot. If you're on the motorway with the fan set at 90° the engine will never get to operating temp. 

 

[Peter C]

3 hours ago, Zelandeth said:

Pretty sure I remember reading somewhere that head gasket failure on these only very rarely allows water into the oil but oil in the water in a more common symptom.  Might be that you do have a slightly leaky gasket causing a tiny amount of oil through but not enough to cause any other issues.

Sadly I don't think there's really any way to conclusively prove it without changing it...so I'd be tempted to just keep an eye on it for now.  Do you know if the head has been off before?  If so it could be residue from a historic issue - it can take ages to get rid of oil residue just using water alone.

Might be worth flushing the system with an appropriate cleaner to try to get rid of it and see if it stays gone.

Do keep an eye on the condition of the coolant hoses though as depending on what type of rubber they're made of the oil can attack them internally and weaken them. 

I’ve had the 200E for almost two years now and I don’t recall there being any mayo issues in the coolant when I first got it.

It doesn’t look like the head has ever been off, all the visible gaskets are quite mature.

In my ownership it’s had a couple of coolant flushes, new antifreeze and a new water pump.

[Peter C]

2 hours ago, Pete-M said:

That is definitely running too cool. Most Merc engines run at between 90°-100° or they're not happy. 

Having the electric fan set at 90° won't help as you're cooling the engine just as it reaches operating temperature. I'd set it at 100° ish so it kicks in when things begin to get hot. If you're on the motorway with the fan set at 90° the engine will never get to operating temp. 

 

The correct running temperature of the M102 engine is 87 deg C. That’s the temperature at which my W123 230E has run for the past ten years, rain or shine, ditto all the other W124s that I’ve had over the years.

Bearing in mind that the engine temp doesn’t get near 70 deg C on a run, changing the electric fan setting to 100 deg C will make no difference to the overcooling issue.

[GBJ]

The thermostat isn't working correctly. It may be stuck partially open.

[Peter C]

9 minutes ago, GBJ said:

The thermostat isn't working correctly. It may be stuck partially open.

I’ve fitted two new thermostats to cure the problem, including a genuine MB part. Neither made any difference.

[Pete-M]

I've owned and driven Mercedes for decades, including W123, 124, 126, 210, Sprinters, Vitos and currently an AMG 203. 

Never known a correctly running Mercedes that didn't run at around 90° all the time. 

The only one I had that ran cool was fixed by replacing the thermostat. As you've done that, the next thing I'd do would be checking the temp sensor isn't on the fritz. 

[Conan]

On 3/30/2020 at 6:02 PM, Peter C said:

 

Something I learned yesterday, there was a W124 280E, which had a phase 2 body fitted with an M104 2.8 engine, as found in phase 3 cars. I knew that a 220E existed (based on the same arrangement as the 280E) but I've never seen a multi-valve petrol six cylinder engine under the bonnet of a phase 2 car.

 

 

Seems odd to me that you've never encounter these, but I understand as they're really a one year only thing!

 

Temp sensor is the next logical step to look into solving this cold running issue, as I believe it is linked to the operation of the electric cooling fan. Unless it simply is just wrong and the car isn't running cool at all.

 

Edit: I know it is troubling because it could also be head gasket failure. But always try cheap, simple fix before going for more difficult one, right?

[BorniteIdentity]

From memory there are two thermostats for the m102 - 88 and ninety something. 88 is what my w201 with the same engine had.

As Zel says they very very seldom show coolant in the oil. The head gasket (when failing) begins to let go right at the back of the engine (as you look at it) allowing oil to   make its way into the coolant and show as gravy in the coolant bottle. Eventually when there’s too much it comes out of the overflow tube into the engine bay. 

Good news here is this is all totally irrelevant and is likely just something trivial.

It’s a smashing example. 

[mat_the_cat]

I'd agree with the thermostat diagnosis normally (you can have as much airflow as you like, but a correctly working thermostat will just close off to keep the temperature up), but fitting two replacements makes this seem less likely!

So I'd be checking for incorrectly plumbed pipes, which may allow coolant to bypass the thermostat. Assuming the 'stat is sealing to the housing correctly, and there's nothing significant bypassing it? 

[paulplom]

The autoshite repair would be to cover some cardboard in tin foil and cable tie it in front of the radiator. The reduced airflow will have it up to temperature/over heating in no time.

[HMC]

Might be worth checking the top hose carefully- someone may have fitted an inline stat (one they had lying about that would fit from another vehicle) which is playing up despite your mb one behaving normally. Long shot - and more common where the factory stat location is somewhere hard to get to (not the case here but otherwise I’m all out of ideas)

[GBJ]

11 hours ago, HMC said:

Might be worth checking the top hose carefully- someone may have fitted an inline stat (one they had lying about that would fit from another vehicle) which is playing up despite your mb one behaving normally. Long shot - and more common where the factory stat location is somewhere hard to get to (not the case here but otherwise I’m all out of ideas)

How would that make it run cool?

[HMC]

1 minute ago, GBJ said:

How would that make it run cool?

Good point, ?

[Peter C]

On 3/30/2020 at 12:20 PM, lesapandre said:

Gosh the mats are that valuable!

Taken from Facebook.

[Peter C]

On 4/2/2020 at 7:50 AM, paulplom said:

The autoshite repair would be to cover some cardboard in tin foil and cable tie it in front of the radiator. The reduced airflow will have it up to temperature/over heating in no time.

Scroll back to page 6, I’ve already tried reducing air flow to the front of the radiator.

 

During winter months this bodge increased the running temperature a bit but once the weather warmed up, the engine temperature was too high, especially when driving around town,  causing the original fan (this was before I fitted the electric fan conversion) to kick in too often.

[lesapandre]

Peter - I will keep my eyes peeled for any mats. Our local scrappy had a W124 in but it had gone before I had time to see it. If I see any mats I will message you if you are still looking. 

[Peter C]

On 4/1/2020 at 9:33 PM, mat_the_cat said:

So I'd be checking for incorrectly plumbed pipes, which may allow coolant to bypass the thermostat. Assuming the 'stat is sealing to the housing correctly, and there's nothing significant bypassing it? 

All the coolant plumbing is original and in good condition. The only mod I’ve made is the electric fan conversion.

The thermostat sits snuggly in a new housing.

[Peter C]

4 minutes ago, lesapandre said:

Peter - I will keep my eyes peeled for any mats. Our local scrappy had a W124 in but it had gone before I had time to see it. If I see any mats I will message you if you are still looking. 

Yes please! I’m happy with the EBay mats for now but would like a good set of original blue or black mats.

[lesapandre]

7 minutes ago, Peter C said:

Yes please! I’m happy with the EBay mats for now but would like a good set of original blue or black mats.

Will do. 

[Peter C]

I’ve been keeping busy during the lockdown. Both Tucsons needed a wash, which killed a couple of hours.

Having done a few engine oil changes on both Mercs in recent years, I’ve accumulated a few gallons of used 10W40 oil. A quick Google search revealed that old engine oil makes for a good wood preservative. I have an arrangement of old timber beams making up flower beds in the rear garden. The beams have weathered silver grey and started to look a little unsightly. A quick coat of brushed on old oil sorted them right out.

The wood was touch dry within the hour. The oil doesn’t smell and has really brought out the grains.

[mat_the_cat]

On 4/2/2020 at 7:50 AM, paulplom said:

The autoshite repair would be to cover some cardboard in tin foil and cable tie it in front of the radiator. The reduced airflow will have it up to temperature/over heating in no time.

Why would it? A correctly functioning thermostat would just close off to some extent once it dropped below temperature.

If you think about it, a radiator should be sized to keep the engine cool whilst towing a trailer up a hill in the middle of summer, so most of the time it'll not need the full cooling capacity. Hence it'll spend most of the time partly shut.

[Peter C]

After a week of standing unused in the garage, I fired up the 200E and within less than ten minutes the engine reached full operating temperature.

[SiC]

Missing cowling in the engine bay, damaged fixing on the undertray allowing it to pull down at speed? Thinking too much airflow - not from flowing in the front through the radiator but loosing heat out of the engine bay. 

[Peter C]

56 minutes ago, SiC said:

Missing cowling in the engine bay, damaged fixing on the undertray allowing it to pull down at speed? Thinking too much airflow - not from flowing in the front through the radiator but loosing heat out of the engine bay. 

Cowling is present and correct.

Undertray is a big metal plate securely fixed with four bolts.

Apart from the electric fan, which is fitted in place of the original fan, everything in the engine bay and below it is stock, present and in good condition.

[Peter C]

A conversation with a friend prompted me to compile a list of all the cars that I've ever owned. Here goes, in chronological order. I've also included cars that I've bought for my wife.

1. Austin Mini 1275GT

2. Austin Mini 1000

3. Ford Fiesta Mk1 1.1L

4. Austin Mini 1000

5. Ford Fiesta Mk1 1.1L

6. Triumph Spitfire Mk IV

7. Ford Fiesta 950 Popular

8. FSO 1500

9. Vauxhall Astra Mk2 1.3L Estate 5 door

10. Ford Sierra 1.6L

10. Porsche 924

11. Citroen AX GT

12. Dutton Pheaton

13. Ford Sierra 2.0 GL Estate

14. Ford Fiesta Mk2 XR2

15. Saab 900 2 door

16. Alfa Romeo Sprint 1.5 Green Cloverleaf

17. Peugeot 405 SRi

18. Vauxhall Carlton 1.8GL

19. Jaguar XJ40 Sovereign

20. Lada Samara 1500 3 door

21. Mahindra Brave Indian Jeep

22. Mercedes 190E

23. Toyota Mk2 MR2 2.0 GT Rev 1

24. Toyota Mk2 MR2 2.0 T-Bar Rev 2 (spares car)

25. Ford Sierra 1.8L Estate

26. Vauxhall Vectra 2.0 GLS

27. Austin Allegro 1300 Super

28. Austin Allegro 1300 Super (spares car)

29. Mercedes W123 200T

30. Ford Fiesta Mk1 1.1L

31. Skoda Favorit Estate

32. Ford Fiesta Mk1 XR2

33. Mazda 323F 1.5

34. Honda S2000

35. Toyota Mk2 MR2 2.0 GT Rev 3

36. Ford Sierra 1.8 Chasseur Estate

37. VW Bora 1.6 

38. BMW E36 318iS

39. Saab 9000CDE

40. Mercedes 190E

41. BMW E30 325i SE

42. 2007 Honda Civic 1.8 SE 

43. 2008 Renault Megane 1.4 Sportshatch 

44. Mitubishi Shogun SWB 2.5 TDi

45. Mitubishi Shogun SWB 2.5 TDi

46. Toyota Mk2 MR2 2.0 Coupe Rev 1

47. Toyota Mk2 MR2 2.0 G-Limited Automatic Rev 3

48. Mercedes W124 200TE

49. Mercedes W124 230E

50. Mazda Mk3 MX5

51. 2000 Honda CRV

52. Mercedes W123 230E (still have it!)

53. Mercedes W126 300SE

54. Lexus LS400

55. BMW E36 320i

56. Mercedes W124 E200

57. Mercedes W124 300TD

58. Toyota Celica GT Gen 6

59. Mercedes C-Class 180 Sport

60. Audi 100 2.6 Sport

61. Vauxhall Astra 1.4 Estate Mk 4

62. Eunos Roadster

63. 2010 BMW 520d Touring F11 

64. Vauxhall Frontera LWB 2.8TDi

65. Toyota Mk2 MR2 2.0 GT Rev 3

66. C204 Mercedes C Class Coupe 220CDi (company car)

67. Mercedes W124 E220

68. BMW 420d 

69. Mercedes W123 230E (spares car)

70. BMW E46 330Ci

71. 2009 Citroen C4 Picasso

72. 1990 Mercedes W219 CLS 3.0CDi

73. 2007 Mercedes R129 500SL

74. 2000 Porsche Boxster 2.7

75. 2018 Hyundai Tucson SE Nav+

76. 2018 Hyundai Tucson SE Nav+

77. Mercedes W124 200E

And I have a photo of every one of them!

 

 

 

[Peter C]

I found (an embarrassing) photo of the 230E (briefly) fitted with C204 18" AMG wheels, which I removed from my company C-Class Coupe. Proof that old cars must have period wheels.