Loose wires and hose

[500ESpain]

Hi, guys

I was inspecting the engine bay and I found two loose wires. Does anyone know what they are? They go from the back of one of the pulleys (the one over the alternator) to another end that disappears under the passenger side headlight. Seems that someone has been messing with them in the past.

I've also noticed there's a L shaped hose that doesn't go anywhere. Maybe a vent? I'd appreciate any information about it.

Thanks in advance!

 

[gsxr]

The wires are for the air/smog pump clutch.

The hose MAY be the air intake for the air/smog pump but I can't tell for sure from the photos.

 

[500ESpain]

Thanks! So that might be the reason why it barely made it through the emissions test?

 

[gsxr]

Thanks! So that might be the reason why it barely made it through the emissions test?

Nope. The air pump only runs when the engine is cold, to compensate for the rich mixture during warmup, before the engine reaches operating temp.

Emissions test should be performed with the engine fully warmed up, and the air pump is not running, so it would not affect the readings. If you post the data from your emissions test (HC, CO, etc) we may be able to help pinpoint possible causes.

 

[500ESpain]

CO values were as you can see on the picture (idle and under acceleration). That's after the test station guy accelerated the car to warm up the cats, which surprised me because I have a hot running issue I'm dealing with and the test was after a 20km highway drive and maximum ten minute wait before the test. Cats are new high flow Magnaflows; maybe they don't comply with Spanish regulations. I'd swear I replaced the oxygen sensor too but I can't find the invoice for it (I always keep them) so maybe I didn't. I'm getting old and forgetting things I guess.

I'm still trying to find out why the car runs so hot. The picture is from this morning 6ºC/42ºF (chilly spring weather we're having in Madrid these days), mild city traffic, no A/C and the auxiliary fans had to kick in. I have new radiator, thermostat and no obvious leaks. Viscous fan is brand new too (Sachs) but it's my main suspect. I never hear it and I thought it was normal but then I drove a friends E500 and I could clearly hear it. Maybe a defective unit or not properly installed?

 

[mercepor]

Hmmm nice, you have a reiserechner...
Probably defective fan clutch, unfortunately it happens (you have some threads dealing with this issue)
You should have a clear airflow even with cold engine, when warm it is quite noisy

 

[500ESpain]

Yes, I've read the threads so I guess that's the problem. I went for the more expensive Sachs to avoid this...

 

[gsxr]

Yes, I've read the threads so I guess that's the problem. I went for the more expensive Sachs to avoid this...

Another new Sachs may not be any better. Klink discussed this in a thread a few years ago.

However, at near-freezing temps the clutch may never engage. The clutch engages based on AIR TEMP, not coolant temp. The only valid test for the fan clutch is in high ambient temps (80-90°F or more, preferably with AC running, with coolant temp >90°C). If someone else's clutch is engaged and roaring at low ambient temps and cool engine temps, their clutch may be engaging too soon. Neither is good. There is a note about this in the M117 FSM, the concept applies to the M119 as well.

 

[gerryvz]

I replaced the fan clutch with an aftermarket BEHR unit in my M117 (560SEC), and it is VERY apparent when this fan clutch engages over the original one. In any ambient (exterior) temp above around 80-85F and at high speeds (engine RPM above 2500 RPM) the clutch engages with a loud whirrr noise, generally at freeway speeds when the coolant temp nears the 95-100C hash mark on the gauge.

It then very quickly cools things down to the 80-85C level, and then the process starts all over again. There is no question when it engages as it is as audible as anything. You can even hear it over the music playing in the car. At low/idle speeds (caught in traffic or city streets) the clutch doesn't seem to engage - it requires engine RPM.

I replaced the fan clutch in my E500 with a "used" clutch from a 1992 500E that only had 50K miles on the engine. It SLIGHTLY improved things over the original clutch that I had on the E500, but only JUST improved things.

I have a brand new, never installed factory MB fan clutch for my E500 that I purchased a bit over a year ago, but I have not installed it yet. Plan to do that soon, when I have the time.

The bulk of the originally factory equipment fan clutches as installed by MB in our cars were defective from the get-go, and never worked correctly. It seems that current production "Horton" (Sachs Group) branded MB factory fan clutches DO work correctly. I will certainly confirm this when I get mine installed. The M117 "Behr" fan clutch that I installed made a significant difference.

 

[500ESpain]

I haven't heard my clutch engage ever. What worries me is that with a temperature as the other day's (6ºC/40ºF) shouldn't engage even if it's properly working then there's something else wrong.

 

[samiam44]

Sach's sold off fan clutches. The quality from Horton has been better.

 

[Klink]

Are you sure that isn't simply an incorrect GAUGE reading? Bad gauges will do that, as will defective coolant gauge temperature sensors and disintegrated upper engine wiring harnesses. If you have access to a shop scanner, SDS machine, or HHT, check the two coolant temperature readings at the LH module. See if there is good macthing of those readings with each other, and then evaluate how well those align with your instrument panel readings.

 

[500ESpain]

I had the whole cluster checked a few years ago so I don't think that's the problem. The auxiliary fans kick in very often; where do they get the reading from, sensors or gauge?

I didn't get any codes from the sensors. Should I if they were defective?

The engine bay feels really hot when you open the hood.

Maybe dying water pump?

 

[gsxr]

The twin auxiliary fans are triggered by the 2-pin temp sensor.

The dash a gauge reads from the 1-pin temp sensor.

The engine management (LH+EZL) read from the 4-pin temp sensor.

All three of the above sensors are located at the front of the intake manifold.

 

[500ESpain]

Thanks!

Should I get any codes if any of these are faulty?

Could it be the water pump?

 

[gsxr]

Thanks! Should I get any codes if any of these are faulty?

Codes will be triggered if the 4-pin or 2-pin sensors are faulty, meaning disconnected, shorted out, or if the 4-pin sensor has drastically different readings between the two pairs of outputs. But if they are just reading inaccurately (say, 10-20C off) there would not be a code. The 1-pin sensor only connects to the dash gauge, there would NOT be any code if this sensor was faulty. IME, the 1-pin sensor tends to fail reading lower than actual, not higher.

Could it be the water pump?

If the gauge is accurate and you are seeing 105C in near freezing temps, that is unusual... with a new radiator and t-stat, yes the water pump could be an issue. Or a defecating new t-stat (rare, but possible). Did the problem begin after installing the radiator/t-stat/clutch, or has it been doing this for a while and the new parts didn't help?