Auto Box help needed please.

[mccars2008]

Hi there everyone, i am new to the forum. I have just aquired a merc 320ce 94 Lreg, its got the 5 speed auto box in it I am told its the 7225 box. The car seems to drive fine, but when you put the power down you can hear quite a loud whine, it eases of a little once cruising although you can still here it. Ive noticed that even when stationary if you rev the engine you can hear it. Like i say the car drives ok gears change ok kick down works fine and ive just driven the car back home 350 miles like this no problem. But the noise is not really nice. Please can any one help me fix this. Oh i checked the autobox oil level and its bang on the mark and looks quite clean.

 

[dragon]

Put it on diagnostic. It will be analogue tests.

 

[television]

Hello and welcome with your unusual fault as I do not think that its been up before,, the doing it in N is the odd thing out where one would have said it was the differential when pulling.

I would take the car to one of the specialist in this trade circle,, they are all good and they will not cheat you.

http://www.fedauto.co.uk/map.htm

 

[stumpy]

a long shot but i think we need more description of the noise and where in the engine it is. It could be the visco fan meaning the fan is always roaring. My old 124 did this and you would get the noise when stationary. Look up on here for the carrot test.

 

[Bolide]

Do you get the whine revving the engine when stationary? If so it's likely to be a bad bearing on an idler on the serpentine belt

Does it follow road speed rather than engine speed? If so, does it stop on the overrun? Then it's very likely to be the diff whining

If it follows engine speed it's in the engine and possibly autobox. If it follows road speed it's possibly the box, prop bearing, diff or wheel bearing - though wheel bearings don't tend to whine

Nick Froome
www.w124.co.uk

 

[kth286]

mccars

Obviously without being at the car to hear the actual noise it is difficult to be precise, but a highly likely candidate is the belt tightener pulley at the front of the 320 engine.

It is the bearing in the pulley that has failed and the replacement of the pulley will cure the noise.

For other forum members I would mention it is a different design to earlier belt tensioners.

Do not leave it to seize up or wobble as you will suffer damage and additional cost.

It is fairly straightforward as a DIY job providing you get the correct sized pulley from dealer only.

You need full VIN and engine number from your documents.

Do make a note (draw a diagram) how the belt was fitted before you take it off.

Cost of pulley of the order of £40 last time I purchased one (92mm size)

Where you located ?

 

[Bolide]

ro make a note (draw a diagram) how the belt was fitted before you take it off

IIRC the belt path is also in the manual. If the best is worn, replace it. There are two types - one for cars with a/c. one without. The length of the belt is marked on it. If in doubt take the old belt to a dealer parts department

Nick Froome
www.w124.co.uk

 

[mccars2008]

mccars

Obviously without being at the car to hear the actual noise it is difficult to be precise, but a highly likely candidate is the belt tightener pulley at the front of the 320 engine.

It is the bearing in the pulley that has failed and the replacement of the pulley will cure the noise.

For other forum members I would mention it is a different design to earlier belt tensioners.

Do not leave it to seize up or wobble as you will suffer damage and additional cost.

It is fairly straightforward as a DIY job providing you get the correct sized pulley from dealer only.

You need full VIN and engine number from your documents.

Do make a note (draw a diagram) how the belt was fitted before you take it off.

Cost of pulley of the order of £40 last time I purchased one (92mm size)

Where you located ?

Hi David,
I have now taken the car to 2 merc specialists,
1. Said its a plastic oil diverter pipe broke in the gearbox and can be repaired without taking the gearbox off by removing gearbox sump replacing pipe and put new fillter and oil in £250.
2. Was a autobox specialist said sounds strange but will need to have car on ramp to identifie noise. But said what the first merc specialist said is wrong becouse the pipe he said is only on the 4 speed autos and mine is the 5 speed auto. But he checked the gearbox oil level at that time and said the oil level was spot on and looked clean. But will have to wait till monday now so he can have another look.
3. Merc specialist said the car is 14 years old and sounds ok for its age. He said prob just needs a full major service and might clear up the noise. Wants £400.

The noise in question sounds similar to a dry pully, which was my initial thought, but the noise seems to come from underneath the engine near the bulkhead? So not sure about the tensioner you mentioned as if that surely you would hear the noise from the front of the engine at the top?

The noise is not there on idle comes when you give the car some revs when stationary or when you drive and accelerate hard.

Any more Ideas, its not the viscous fan.

 

[kth286]

A car stethoscope is the answer to pinpoint noises around engine etc.

A long piece of wood to the ear is a second best and can work - just be careful when probing a running engine.

The handbook will show which is the pulley refered to, and you just need to place end of wood against the stationary part that pulley fixes to for the answer.

Where you located ?