Following on from the petrol issues of late, I have had my car at the main ford dealer due to severe problems with tickover speed and stalling at low revs (its a 2.0 Petrol auto model).
Stalling as you turn a corner or on a roundabout, in an automatic, can be such fun when the power steering cuts!!
The ford dealer did a diagnostic check and fixed a small rubber t piece on the vacuum system. The subsequent test drive noted the same problem. They then disconnected the MAF Sensor and told me the car needs a new idle speed control valve. This is £120 fitted by them.
Some further research by me has turned up quite a few other possible causes, including
1) Crankcase Breather Valve
2) EGPD Valve (Exhaust Gas Pressure Differential?)
The symptoms of these describe closely the problem i'm having. Mainly - idle is ok when cold. as the engine warms up, the problem seems to be a "pulsing" of the revs, leading to a stall.
Can anyone tell me how good the diagnostic kit is at a main dealer and therefore how likely it is that the part I need is the Idle Speed Control Valve?
Also, if it is this, is £120 too much to pay?
Finally, what is the implications of running the car without the MAF Sensor connected? It seems to run ok, but I would assume that thew ECU will eventually "learn" this and alter the way the car generates power?
Any thoughts would be very much appreciated!
Ta!
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i used to own an 1.8 16 valve petrol escort should be a simlar engine (Zetez) had the same problem i remove the idle controll valve cleaned it with a carb cleaner on simlar the idle valve gets clogged up with carbon and sticks, would be worth wile cleaning it out rather than pay the £120,hope this mite help
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I seem to recall there being a common problem on the early Mondeos with the idle up switch on the power steering failing and causing the engine to stall when the steering was turned at low speeds. I don't suppose you've noticed if it's linked to steering inputs at all? Being an auto, the engine will return to idle, or thereabouts whenever you lift off the gas.
If it is the idle valve (possible), then as dieselpower said, they can sometimes be cleaned up. The worst that can happen is you're going to have to replace it anyway, so why not give it a try?
I too would have changed the T-piece as your Ford dealer did. This is a common fault, and causes pretty much the exact symptoms you describe.
Cheers
DP
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If it has a full diagnostic check the PAS switch is tested during this process. Oil viscosity is critical on this engine so make sure you use 5/30 Z-tec oil its a 100% must. The later idle valves were modified so a new one may help. I recommend you use manufactures spark plugs only as other brands cause excess electrical noise under the bonnet creating a stalling problem by making sensors misinterprate signals ( This is one of the most frequent problems with modern day cars & I have seen Tec's with 20years experience struggle to except this untill they see it for themselves!) I have also had the crankshaft pully rotate slightly on its rubber damper & when a cambelt is replaced the timing is slightly retarded! (common) Wash the throttle body out even though it say's dont because it has a coating on it to stop it gumming up ( never worked ) & I have even drilled a 1.5mm hole in the throttle flap to increase base idle but not for the inexperienced!
regards
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IACV is about £50 supply only, so looks like an hour to fit. Ask them to confirm beforehand that this will cure the problem. Zetec engines require the right plugs with the right gap, they also need Ford plug leads. Coil pack can cause problems.
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Thanks to everyone for your help.
I will get some carb cleaner and clean up all the relevant bits and let you know how it goes.
Anyone got any comment on what disconnecting the MAF Sensor will actually do to the running? WIll it cause longer term problems? The Ford Dealer didn't say either way!
Thanks again!
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OK - I got the carb cleaner today, but... ... ... (!)
The car started running hot on the way home, and stalling at low revs.... .
I checked the water level (after letting it cool) and it needed 2 litres of water! (this is checked weekly)
With the water now topped up, the car won't start! It turns over ok, but seems to be struggling to fire up. Plenty of petrol (is it now flooded?) as I can smell it!
With the MAF sensor disconnected, has something else been damaged? Is there anything else I should consider before getting the dealer to take another look at it?
Please help!!!
Thanks!
S
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It will run richer with MAF disconnected. If the engine hunts at times this could indicate an air leak &/or a lazy IAC valve . I would poosibly consider an independent injection specialist to look at your fault as it will be cheaper than the dealer & from my experience of working for thirty years in dealer ships & independents you usually find the more experienced in a good independent garage as the dealership rates of pay leave a little to be desired. A good tech will raed & interperate the live data information & from that should know whats going on
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thanks for the input - anyone know a good independent within a reasonable distance of Southampton?
S
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EGPD valve normally gives you arratic driving at approx 40mph used to change quite a few. On zetec escourts I have changed quite a few crankcase breather valves for stalling with sucess but can't say I have done one on a mondeo. I have also had auto's where the lock up in the convertor stay's in too long and stalls the car when slowing down!, is the box a little erratic ?
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I can't say i've noticed the box being erratic. no problem at speed either (although a little lacking in power when accelerating) ..
several people have suggested changing thre EGPD valve and also the crankcase breather valve. these are both relatively cheap and will probably help things generally as the car has done 113,000+ miles.
thanks for your help.
S
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Has the metal EGR pipe been checked for cracks as I'm sure they used to crack underneath around the g/box area. it really does sound like a sticky IAC valve &/or air leak . air leak would cause the hunting when hot. I would at least clean the valve ,check for air leaks, this can be done by spraying a penetrating oil from an aresol near suspect areas, dont use anything to volotile! lean back and don't use anything with silicons in it & listen for a change in idle speed.If it changes you have found an air leak.
Remove 3amp fuse for ECU ( keep memory alive ) for ten minuets then refit fuse & restart hot. don't rev it just let it idle for 5mins then drive for ten
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When the dealer fixed the rubber t-piece I guess that indicated a leak in the pressure/vacuum system. I'll do these checks too to make sure there's not anymore leaks anywhere!
And an update -
I have cleaned the Idle Speed Control Valve and MAF sensor with Carb Cleaner today! Thanks to everyone for your guidance on how to do this!
Things are definitely running more smoothly, although there is some "hunting" when hot.
One other thing has now gone! The water pump!
Is this a big job? I've been quoted £120 plus VAT and parts! I'm guessing this may have gone because of running hot due to the mix being rich with the MAF sensor disconnected?
WIth the MAF now connected again and the idle being more normal, I'm hoping the water pump will be the last thing to fix!
Thanks again to everyone for your help!
S
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Sorry if i'm being a bit dumb here (!) but...
I say the water pump has gone, but there is a good flow through the system.
Why do I think it has gone? Because when the system is pressurised there is water leaking onto the drive belt and "spitting" up onto the inside of the bonnet. This is where all that water has been going!
Is this likely to require a new water pump, or is it a case of something else down there could leak when pressurised? Or could it simply need a new gasket on the water pump housing?
Still a little unsure!
S
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