Car starts then sits at 0 revs 10 sec

[purple71]

I have a 2010 fiesta tdci, regular service 87,000 miles new cam etc 4,000 miles ago , looked after car. 

 

 

 

I drive to work and park up in the car park and then .. back to car less than 5 hours later On start up only in the multistory car park (damp and cold ) starts fine then revs stay at 0 for about 10 secs oil light stays on, cannot rev the car. Sounds very chuggy. Rev counter the jumps up to just under 1000, and runs ok. This only happens in multistory car park. Parked on level 0 flat.

 

 

 

At home I park either on drive steep or road and car starts first time no problem.

 

 

 

it's been to the garage full service and oil change 3 weeks ago. They ahve seen a video of the problem and cannot find anything wrong. Starts no problem anywhere else even stood for 4 to 5 days in the cold. Just in this car park 

 

 

 

Noone seems to be able help is this damaging my car ? 

 

 

 

Any help appreciated

 

 

[rd457]

It's hard to get a good handle on what you're trying to describe. Could you share the video please?

Just a complete shot in the dark considering the manufacturing year - try giving the dash a whack above the instrument cluster when it's misbehaving. If this makes a difference then this suggests that you're suffering from the infamous cracked solder joint issue. This doesn't always work, so maybe try on a few different occasions before giving up on this. If it is this then it's time for an act of shameless self promotion - I have my own repair service for it (garages aren't typically interested in fixing it themselves I believe, they'd just want to replace it at great expense).

How confident are you that this garage is actually doing the work you've paid for? I've seen cases online where people having been paying for oil changes and later found out the hard way that it was never actually done.

It may be a good idea for you to simply take it to a different garage to see if they do any better at figuring it out.

Again, it would be really helpful for us to be able to see that video.

[purple71]

https://photos.app.goo.gl/bahsSx2yGexDJMdX9

thank you for the reply

I am not sure how to add a video as its larger than allowed, I have created the link above, not sure if it will work

The car starts but chuggs slowly and loudly the rev counter stays 0 and the oil light stays on, after about 9-10 seconds the engine noise changes to run normally and the rev counter jumps to normal and the oil light goes off. car runs normally

The cars starts normally anywhere else,even after being sat for a few days this is only happening in the multistory car park.( its where i need to park for work unfortunately) 

The garage are very good and always had good work , so we do trust them.

[rd457]

Okay yeah I follow. Thanks for the videos, that did help.

So we've got three symptoms, all of which disappear together after several seconds, and the problem is happening only when parked in a certain location...

Let's assume the oil really is in a good condition then.

I'm thinking that the chuggy engine symptom is probably just because the ECU/PCM (engine management computer) is confused, perhaps getting bad data or no data for one or more inputs, in which case you probably don't need to worry much about damage.

With the oil light being on, perhaps the oil pressure sensor could be involved in such a data issue, or perhaps it's just a red herring. Perhaps the ECU/PCM being confused is just never getting to a point of turning it off until the problem rights itself or is choosing to stick it on as a precaution.

The most interesting detail to me is that lack of tachometer (rev counter) reading reaching the instrument cluster. Clearly the engine is turning over so why does it read zero? The needle jumps up nice and smoothly as soon as the problem vanishes so it doesn't look to me like the gauge motor is faulty and besides we have the other symptoms, so it must be not getting the reading somehow.

I saw that the fuel gauge seems to be working. On my Focus the fuel gauge sensor is connected directly to the instrument cluster, whilst rev counter readings are not and must presumably be coming from the ECU/PCM via CAN bus messages. So are these messages failing to reach the instrument cluster, perhaps due to the cracked solder issue (not all pins crack identically)? Or is the ECU/PCM not getting a (valid) reading to transmit? Or, is something else tripping up the ECU/PCM such that it never gets to a point of sending the messages? There are various other warning lights that start on and then go out as normal; is this because of successful CAN bus communications, suggesting communications are getting through fine? (Mileage is stored in the instrument cluster so that showing up means nothing; no idea where environment temperature comes from).

This is the point where a mechanic might plug their OBD device into the car's diagnostic port to examine the data, gaining a better insight, but without that I'm stuck guessing and theorising. 😕

Turning to google, I turned up some discussions of similar symptoms on different brands of vehicles, e.g. 0 revs and oil light blinking until they rev the engine on an Audi. Someone suggested that the rev count comes from the alternator and so it could be an alternator issue. I believe one person said replacing their alternator fixed it for them. There was a suggestion to check the wiring connector (not the main power wire - be careful) on the alternator for contamination. One person said cleaning that made no difference but did find that cleaning a connector on their clutch housing worked.

That research does then suggest that it is an electrical problem perhaps specifically involving bad/no tachometer input, possibly due to contamination in a wiring connector, or a faulty alternator.

As for the problem only occurring when parked in the multistory, were you saying that this is the only level place you park? I can only shrug and suggest that the cause is contamination of a fluid form.

Since you said that you just had your oil changed only a few weeks ago, and since mechanics sometimes spill said new oil, if I had money to gamble with I'd put in on some spilt oil having gotten into a wiring connector. Or some got into the alternator and is somehow causing havoc in it. Or perhaps they washed off spilt oil with water or something and that got into one of these things?

Why does it stop after a few seconds... 🤷‍♂️ I don't know, I give up. I don't think adding speculation on that would be useful. 🙃

So I'd get back to the garage and have them investigate the alternator and wiring based on the above, unless you want to look yourself.

[purple71]

 Hi thanks for the reply. I will read in more depth . 

Just to add, this was happening before the service, i thought maybe old oil was causing an issue there had a complete full service . And it only happens in the multistory car park. No matter where I park in there it happens . Not anywhere else ever has it done this either  on a slope or a flat .

I dont know anything really about cars but would a problem with the tachometer / electrics cause the engine to run judder and slow for those few seconds ? I wonder if its the cause or an effect of the engine being juddery. 

But the ideas you have given are very helpful and in depth, we have spoken to alot of people who cannot work it out ex mechanics as well. It's just woerd it only happens in that multistory car park 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

I am not sure on how to post the video as it is larger than allowed. Garage is very good honest and has always been reliable with other cars in past.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

It's not a instrument fault. 

 

 

 

The car starts but very chuggy , the rev counter stays at 0 after 9 -10 seconds the engine seems to correct to the right "speed" and then the rev counter jumps to where either should be at this point I can rev it. 

 

 

 

As I say it only happens in this multistory. I have asked other mechanics noone seems to be able to say what it could be 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

[RL123]

About 1990 in the early days of ABS, police cars had the abs switch off every time they keyed their microphone. RF interference was the cause and had to be shielded.

I had a 1978 Opel and when I keyed the CB radio mic, the wipers started. People have found on some petrol station forecourts, their key fobs fail to unlock or start their cars. Unlikely in your case but just a thought.

[TomsFocus]

2 hours ago, purple71 said:

I dont know anything really about cars but would a problem with the tachometer / electrics cause the engine to run judder and slow for those few seconds ?

Yes.  The rev counter is used by the engine ECU to calculate how much fuel to inject to keep the fuel:air ratio perfect.  If the ECU doesn't know the engine speed, it will just use a 'failsafe' method of dumping lots of fuel in just to keep the engine running.

I'd suggest this is a fault with the engine wiring loom myself.  Most likely a dodgy plug that is exacerbated by the cold & damp in the multistorey.

[rd457]

12 hours ago, purple71 said:

Just to add, this was happening before the service... And it only happens in the multistory car park. No matter where I park in there it happens . Not anywhere else ever has it done this either  on a slope or a flat .

Oh okay.

12 hours ago, purple71 said:

I dont know anything really about cars but would a problem with the tachometer / electrics cause the engine to run judder and slow for those few seconds ? I wonder if its the cause or an effect of the engine being juddery. 

Yes, as I indicated before and Tom has helped clarify, the engine management computer is responsible for controlling the engine and if it's in a state of confusion due to bad or missing data inputs then this can explain the engine performing strangely. I feel very confident that this missing tachometer reading is the key here.

Conversely the idea of the engine running rough being the cause doesn't give any explanation for why the tachometer is reading zero.

So as before, I feel that the wiring connections need to be looked at and otherwise the alternator itself.

[purple71]

Thank you all I have something to work on. I am sure its something to do with being cold and damp in the multistory , maybe the car being cold and damp over the winter has caused this. 

 

 

 

 

 

 

 

 

 

 

[RichM]

Hi,

 

Did you ever get to the bottom of this problem. My son's 2010 1.4TDCI has the exact same problem.