Air flow related problems continue

[GenesisRed]

Read this for background if you wish. http://www.projectpuma.com/viewtopic.php?f=25&t=12280" onclick="window.open(this.href);return false;

As summary, after a long journey with lots of nose to tail traffic London to Birmingham, the car developed a problem which caused it to stall itself at the lights 5 minute from destination. To be precise, when I tried to move off, I blipped the revs as normal and they died as soon as I let out the clutch. It started again, but as it started to die I revved it higher and it moved off. The oil now was below the minimum, which i immediately replenished. Next day it seemed ok, and made the journey home fine.

The other day, it started again after it got hot in traffic. Later in the same journey, after having to give significant throttle management to keep the revs up when moving off, it finally refused 5 minutes from home. It then refused to start all together and the oil light came on. I called RAC and they gave me the code readout which pointed to the crank shaft sensor. I changed that. No change, once it got hot.

Next we changed the mass air intake sensor. That seemed to be fine (in short distances yesterday) until today when I got caught in traffic for 25 minutes on the A2, and it started up again... I was able to get off and come back home, where there wasn't traffic, and it settled down when moving, though still there when I had to pull off at lights.

Any suggestions?

I'm trying a different garage and getting some advice, but a sense check would be very welcome as my better half is less inclined than me to continue spending money on it.

Would a lambda sensor really have that affect? Once the car is in motion it is fine, and it only happens when it is fully hot. What else could there be?

Thanks for any and all help!

 

[GenesisRed]

Let me just add that it only happens around 1000 to 1500 revs, and only when hot. When in motion it is fine, just when standing or starting the engine when hot.

It revs fine otherwise, so it doesn't seem like spark related, but then I know nothing.

 

[yippeekiay]

Does the fan come in to cool the car down at all or does it not get that hot before playing up?? What does the temparuture guage say when it is playing up.

 

[GenesisRed]

The temp gauge doesn't seem to shift as far as i've noticed, but i've not given it that much attention. It just goes up to middle then sticks there. It never happens before it's been at the middle for at least a little while.

As far as the fan, honestly I haven't heard it but i would expect that it has come on after 25 minutes in traffic and a 40 minute drive.

I'll give it a drive later when the roads are quieter and without the radio on and see.

 

[yippeekiay]

I'm just thinking out loud that's all...if it's overheating and not being cooled that can't be good in any shape or form and may be why you used your oil unexpectedly as it was basically being burned off when very hot. Countless other problems could be caused by such a situation. If you can determine that it is working then it's something you can at least cross off the list k:

Not very helpfull but efficient cooling is something on my mind currently thus the reason I mentioned it and have fitted an auxillary fan switch only today....lol.

 

[GenesisRed]

That sounds like something I can easily check. I assume it's pretty obvious when the fan comes on? Had overheating problems on the last car I owned (BMW 328i nightmare).

Don't pumas have a thirst for oil anyway?

Just stumbled on this also: http://www.fixya.com/cars/t1581563-ford_puma_cuts_out" onclick="window.open(this.href);return false; which suggests fuel filter or fuel pump as a possibility.

Does it sound likely?

Cheers for your help and thoughts!

 

[yippeekiay]

Oil consumption - some do, some don't

Fuel filter - cheap to change and easy too. If you don't know when it was last changed it's worth doing for the minimal outlay

Fuel pump - a quick check would be when you first turn on the ignition before starting to see if you can hear it humming a way while it primes your system. Unfortunately this doesn't tell you how efficient it is and I can't see why it or the filter would be affected due to how hot your engine is.

 

[ScubaSteve]

any blue smoke?

 

[hotrodspike]

Also try, Power steering fluid level, if it's very low the revs will try to compensate for no assistance. Also related, try the power steering sensor on the PS pipe bottom of the radiator. The cables leading to it get very brittle and break, giving the same sort of effect as the above.

 

[GenesisRed]

Not aware of any blue smoke, and no obvious noises from pumps (or fans for that matter, though it must surely have kicked in on the 20 minute blast from lakeside shopping centre to Greenwich just now).

So, as suggested there, I took it for a spin, and it showed no obvious signs when there was no traffic. However it was a little unwilling to start without a heavy lick of throttle even after an hour of sitting in the cool. But again, no probs on the way back, even at the minor hold up of a couple of lights and roundabouts.

So I can trust it on medium journeys unless there is traffic. Well, that should be great in London then! :roll:

Thanks all for your continued input! Further thoughts greatly welcomed...

 

[GenesisRed]

Update. No news.

Well, that's not strictly true. When I start it up, it starts easily, but it takes a few second (especially when warm) for the oil pressure light to go out fully. It kind of lingers for those seconds as it fades out.

The oil level is fine, but had (as I mentioned before) gotten low after a long journey. It is also the light that came on and refused to go out when I had to call the RAC to come get me. Once it had cooled down, it made the remainder distance fine.

Any further thoughts?

No obvious loss of revs or power steering btw...

 

[The Arch Bishop]

Could it be coils starting to break down when they get hot? I've seen this happen on other cars and it gives similar symptoms. It may also give the crank sensor code that you mentioned as I'd imagine the timing would be all over the place. I may, however, be talking nonsense!

Also, while they changed the crank sensor, did they check the wiring going to and from it? Again, the cable could be expanding and contracting with the heat or breaking slightly when the engine moves on the mounts. This would be most obvious moving away as the engine would probably be experiencing the most torque twisting when moving off from stand-still. I had a golf that had the cable damaged and would die entirely at this point. You could check it by finding the wiring and giving it a fiddle when you first start the car.

 

[hotrodspike]

Take off the coil pack (couple of screws) turn it over and have a look if there's any black "tracking" marks in the gel. If there is you'll need a new coil pack.