Car mechanical questions

[the_lone_wolf]

OK, two completely unrelated questions about car engines that i'm throwing myself upon the org for help answering...

1: My 53 plate diesel ford focus is making a squealing noise when you start it from cold, after a few miles it's gone as the engine is warming up but it's getting gradually louder/longer lasting and more annoying. i'm thinking it could be a belt however it doesn't rise or fall with engine revs. it's also begun, in the last few weeks, to stumble when you start it cold, not all the time, perhaps once or twice a week

2: My mum is looking to purchase a BMW 320d, which has 66k on the clocks - it belongs to a close friend of mine so i'm certain he's not trying to screw us or anything, however, the turbo is making a whining noise when it's cold, not very loud but certainly noticable in the cabin. my natural reaction to turbos making whining noises would be to run to the hills however he's as concerned as we are, has taken it to two different BMW centres and they've said that the turbo is fine. is there any BMW knowledgable mechanics out there who might be able to advise as to what might be going on?

[Gazza77]

Originally Posted by the_lone_wolf

OK, two completely unrelated questions about car engines that i'm throwing myself upon the org for help answering...

1: My 53 plate diesel ford focus is making a squealing noise when you start it from cold, after a few miles it's gone as the engine is warming up but it's getting gradually louder/longer lasting and more annoying. i'm thinking it could be a belt however it doesn't rise or fall with engine revs. it's also begun, in the last few weeks, to stumble when you start it cold, not all the time, perhaps once or twice a week

2: My mum is looking to purchase a BMW 320d, which has 66k on the clocks - it belongs to a close friend of mine so i'm certain he's not trying to screw us or anything, however, the turbo is making a whining noise when it's cold, not very loud but certainly noticable in the cabin. my natural reaction to turbos making whining noises would be to run to the hills however he's as concerned as we are, has taken it to two different BMW centres and they've said that the turbo is fine. is there any BMW knowledgable mechanics out there who might be able to advise as to what might be going on?

Can't say there is a fault, but IIRC I'm sure I've seen a couple of articles about the 2 litre BMW diesel engine blowing its turbo. Might be worth looking up a BMW forum. Can't comment on the Focus, sorry.

[the_lone_wolf]

ok, i'll have to do a bit of digging about the BMW as a cursary google search reveals a couple of people mentioning the 320d as a weak engine

thanks

Buy my 525TDS SE off of me, it has 90k on the clock and has only ever been owned by me and my father in law! Has a full history, last couple of stamps BMW specialist, I have used for years.

Grey leather, blah, blah, blah..............

[G]

A Squeling noise with the focus. Without hearing the noise its hard to diagnose......but it could be the clutch release bearing, that will make a squealing/whistling noise when worn, once warmed up the noise will go like you describe.

Otherwise I would say belt, however this would be effected by engine speed.

The BMW I wouldnt like to say.....

I have had various turbo diesels, my 1.9dci Laguna's turbo whislted and then had a crap load of turbo problems (amongst others). My 306 hdi before that whistled and was one of the most reliable engines i have had to date.

The fact it does it only when cold would bother me, it could be innocent in that the fueling/boost has been adjusted electronically when cold like a choke. Or it could be making a noise because the bearing within the turbo are on their way out and not oiled sufficiently when cold.

[the_lone_wolf]

Originally Posted by graemepaterson

A Squeling noise with the focus. Without hearing the noise its hard to diagnose......but it could be the clutch release bearing, that will make a squealing/whistling noise when worn, once warmed up the noise will go like you describe.

- i'll try and take a video of the noise this afternoon and upload it to youtube so you can here what it sounds like

Or it could be making a noise because the bearing within the turbo are on their way out and not oiled sufficiently when cold.

this is what my initial thoughts were

[G]

Originally Posted by the_lone_wolf

- i'll try and take a video of the noise this afternoon and upload it to youtube so you can here what it sounds like

Also try depressing the clutch pedal fully and see if the noise/tone changes, if it does change when pressinf the clutch pedal to the floor then its likely the problem.

See it a few times on french car, the part is normally £7 but then you have to be capable of whipping the gearbox off to save on labour costs.

Originally Posted by the_lone_wolf

this is what my initial thoughts were

Bear in mind turbos do whistle anyway, a smooth progressive whistle i would describe as normal, a more mechanical rattly whistle would be a problem, but again getting to listen to it would give more of an idea.

I'm no mechanic but have owned 5 french cars all of which were a problem and all of which bar a except the 306 I was ripping bits out of the engine, thats before any mention of working on friends cars which were also french.

If we didnt work on them we would have spent a fortune.

[Luckypants]

Originally Posted by Gazza77

Can't say there is a fault, but IIRC I'm sure I've seen a couple of articles about the 2 litre BMW diesel engine blowing its turbo. Might be worth looking up a BMW forum. Can't comment on the Focus, sorry.

320d has had a few turbo problems. Not sure about current models, as most of the guys I know had them on 3 year company car deals and mostly they swapped to Honda or Lexus after the 3 series (depending on their financial position).

[embee]

What you describe of the squeal sounds very much like the alternator belt slipping. The frequency of the noise isn't engine speed related, mainly a fuction of the belt construction (stick/slip of the rubber on the pulley).

Drive belts tend to tighten as the unit gets hot (the structure expands), assuming it doesn't have an automatic tensioner, so the slipping reduces when hot. Rechecking the tension should fix it, though if the belt is tired it's worth replacing.

Immediately after a start the alternator is heavily loaded trying to recharge the battery. From your description of stumbling I'd begin to suspect the battery itself anyway. This sort of stumbling, or stalling even, can happen if the battery voltage recovery doesn't match the expected characteristics under which the ECU is programmed.

I had a van once on which I thought the alternator was on its way out because it rumbled after a cold start. That turned out to be the battery (it died completely soon after), it was so knackered the poor alternator was running flat out trying to charge it. It's surprising how much noise alternators can make under full load.

[the_lone_wolf]

Originally Posted by embee

What you describe of the squeal sounds very much like the alternator belt slipping. The frequency of the noise isn't engine speed related, mainly a fuction of the belt construction (stick/slip of the rubber on the pulley).

Drive belts tend to tighten as the unit gets hot (the structure expands), assuming it doesn't have an automatic tensioner, so the slipping reduces when hot. Rechecking the tension should fix it, though if the belt is tired it's worth replacing.

Immediately after a start the alternator is heavily loaded trying to recharge the battery. From your description of stumbling I'd begin to suspect the battery itself anyway. This sort of stumbling, or stalling even, can happen if the battery voltage recovery doesn't match the expected characteristics under which the ECU is programmed.

I had a van once on which I thought the alternator was on its way out because it rumbled after a cold start. That turned out to be the battery (it died completely soon after), it was so knackered the poor alternator was running flat out trying to charge it. It's surprising how much noise alternators can make under full load.

i'm inclined to think this is the likely cause here, i sat in the car in the office car park when i left work and tried revving the engine and depressing the clutch, the revs might have affected it slightly but the clutch did nothing so thankfully it doesn't sound like that problem.

also, it was very very wet out there this afternoon and the squeal wasn't anywhere near as bad as it had been this morning when i started it in the dry, i'd imagine the water lubricates the belts allowing them to slip, which can't be good for the alternator or battery.

when i said stumble btw i meant before the engine catches, instead of the normal "chu chu chu chu *start*" it's more like chu chu chu ku-chu ku-chu ku-chu chukka-chukka *start* - you'll have to provide your own sound effects...