HARMLESS VAPOUR
Q: There is engine oil entering the inlet manifold of my Omega 2.5TD. Do you know why this is happening, whether it's harmful, and what I can do to combat it? Many thanks!
Posted by: harksb
A: You'll find this happening on most, if not all turbodiesel engines. The oil is from the crankcase breather system, which vents oil vapour and gases from the crankcase (sump) area of the engine, and introduces them to the inlet manifold for burning in the cylinders as an anti-pollution measure. The hot oil mist condenses on cooler manifold walls and causes oil to accumulate, but it's harmless.
COULD THIS BE THE BIG END?
Q: The oil light of my M-reg Vauxhall Cavalier keeps coming on then going off, and the engine has started making loud knocking noises. Do you think these two symptoms are related, and can I keep driving the car?
Posted by: andrea_490
A: At a guess what's happening is that the engine's big ends are worn (causing the clonking noises) and that wear is also lowering the engine oil pressure, causing the warning light to come on. If we're right, you'll be needing an engine overhaul or a replacement engine.
MONDY DOESN'T LIKE QUEUES
Q: Our Ford Mondeo 1.8LX has covered 57,000 miles and we recently made two long journeys in it, each time getting stuck for 45 minutes in nose-to-tail queues. During this time the temperature reading went two-thirds of the way up the scale, but came down again when we started moving. Why?
Posted by: rob.meadows
A: Well, Rob, it's called 'engine overheating', unfortunately. But the engine is not overheating when you're moving because air is being forced through the radiator. What's supposed to do that when you're not moving? Why, the electric cooling fan of course, which in this case appears not to be working!
WHAT'S AN AIR MASS METER?
Q: Can you tell me what an air mass meter is? And how it works? Does it operate on the 'pitot tube' principle, and can it be cleaned to keep it working well?
Posted by: antonbell
A: Woah there! You're getting too technical for us. An air mass meter is a part of fuel injection systems that measures the density of intake air so the system can work out how much fuel to inject. It's a tubular casing with a thin heated filament in it; cooling of this wire varies current passing through it, and that gauges air ingested. Don't try cleaning it though!
BEEMER'S SECRET DRAW
Q: There seems to be a short circuit somewhere in my 1984 BMW 318i that is flattening the car's battery. The alternator has been replaced, so it's not that; where do you think the fault lies?
Posted by: sassyhasmail
A: If the battery is draining when the car is unused, there is clearly an electrical device staying on when it should be off. This could be something difficult to see, like a boot compartment light. Get current draw measured between a battery lead and terminal - it should be no more than 1 amp, allowing for clock, alarm system, radio memory etc.
PLENTY OF SUN... BUT NO FIRE!
Q: MY 1996 Pontiac Sunfire 2.2 stalls whenever the outside temperature is warmer then 60 degrees and the engine is at optimum operating temperature. It will restart immediately though, and will be okay for five minutes or so.
Posted by: mikechoiselat
A: We assume you mean degrees Fahrenheit, yes? If it's degrees C then there's the explanation! Either there's fuel vaporisation occurring (usually a trait of carburettors) or one or more temperature sensors around the engine management system are giving incorrect readings. You'll have to wheel it into an injection specialist - sorry! A RELUCTANT ROVER
Q: I have a Rover 45 diesel. When I start it from cold I have to hold down the accelerator and wait for the revs to go above 2000. If I don't, there is absolutely no acceleration power.
Posted by: keith
A: This could be due to air locks in the low-pressure side of the fuel system (tank to injection pump). If it eventually clears, that confirms it. If so, check the tightness of every union in that system right up to the pump. It's also possible the fuel filter is congested, or the fuel return pipes (connecting the injectors) are obstructed. THIS MERC DOESN'T DO MORNINGS
Q: I have a 1992 Mercedes-Benz 190E 2.0i and have trouble starting it first thing in the morning. Once it has started it then starts first time every time throughout the day. Any idea why?
Posted by: Barbarahope05
A: You haven't said whether it's trouble cranking the engine over (reluctant or slow starter motor) or whether it churns okay but just won't fire. In the former case you need to check battery condition, the starter motor, its solenoid and supply circuits. In the latter case there's a fault either with the ignition system or fuelling, but only a workshop can tell which.
CLIO TELLTALE ALL AGLOW
Q: The battery indicator light of my 1994 Renault Clio 1.9D has come on, but the battery has been checked and is okay, and I've recently had a new alternator and fan belt fitted. What do you think the problem could be?
Posted by: lisamichellespence
A: If the new alternator was fitted correctly, and the battery and connections are fine, there's something wrong in the supporting circuitry - assuming no bits (such as rectifier or regulator) were carried across from the old alternator. It's also possible there's a fault with these on the new unit, and either way you need an auto electrician.
IS LANDIE LOSING ITS HEAD?
Q: My son's W-registered Land Rover Freelander 1.8 had a new head gasket fitted about six months ago. But the coolant level is dropping again, and we're finding water on the drive.
Posted by: mel
A: The engine could be overheating; is the fan working, and does the gauge ever read high? It could also be that the coolant has dropped because there was an air lock (no passed) and that the dripping water you're seeing is normal condensation from the air conditioning. A garage can do a chemical check of the coolant and say if the head gasket is at fault.
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Q: There seems to be a short circuit somewhere in my 1984 BMW 318i that is flattening the car's battery. The alternator has been replaced, so it's not that; where do you think the fault lies?
Posted by: sassyhasmail
A: If the battery is draining when the car is unused, there is clearly an electrical device staying on when it should be off. This could be something difficult to see, like a boot compartment light. Get current draw measured between a battery lead and terminal - it should be no more than 1 amp, allowing for clock, alarm system, radio memory etc.
PLENTY OF SUN... BUT NO FIRE!
Q: MY 1996 Pontiac Sunfire 2.2 stalls whenever the outside temperature is warmer then 60 degrees and the engine is at optimum operating temperature. It will restart immediately though, and will be okay for five minutes or so.
Posted by: mikechoiselat
A: We assume you mean degrees Fahrenheit, yes? If it's degrees C then there's the explanation! Either there's fuel vaporisation occurring (usually a trait of carburettors) or one or more temperature sensors around the engine management system are giving incorrect readings. You'll have to wheel it into an injection specialist - sorry! A RELUCTANT ROVER
Q: I have a Rover 45 diesel. When I start it from cold I have to hold down the accelerator and wait for the revs to go above 2000. If I don't, there is absolutely no acceleration power.
Posted by: keith
A: This could be due to air locks in the low-pressure side of the fuel system (tank to injection pump). If it eventually clears, that confirms it. If so, check the tightness of every union in that system right up to the pump. It's also possible the fuel filter is congested, or the fuel return pipes (connecting the injectors) are obstructed. THIS MERC DOESN'T DO MORNINGS
Q: I have a 1992 Mercedes-Benz 190E 2.0i and have trouble starting it first thing in the morning. Once it has started it then starts first time every time throughout the day. Any idea why?
Posted by: Barbarahope05
A: You haven't said whether it's trouble cranking the engine over (reluctant or slow starter motor) or whether it churns okay but just won't fire. In the former case you need to check battery condition, the starter motor, its solenoid and supply circuits. In the latter case there's a fault either with the ignition system or fuelling, but only a workshop can tell which.
CLIO TELLTALE ALL AGLOW
Q: The battery indicator light of my 1994 Renault Clio 1.9D has come on, but the battery has been checked and is okay, and I've recently had a new alternator and fan belt fitted. What do you think the problem could be?
Posted by: lisamichellespence
A: If the new alternator was fitted correctly, and the battery and connections are fine, there's something wrong in the supporting circuitry - assuming no bits (such as rectifier or regulator) were carried across from the old alternator. It's also possible there's a fault with these on the new unit, and either way you need an auto electrician.
IS LANDIE LOSING ITS HEAD?
Q: My son's W-registered Land Rover Freelander 1.8 had a new head gasket fitted about six months ago. But the coolant level is dropping again, and we're finding water on the drive.
Posted by: mel
A: The engine could be overheating; is the fan working, and does the gauge ever read high? It could also be that the coolant has dropped because there was an air lock (no passed) and that the dripping water you're seeing is normal condensation from the air conditioning. A garage can do a chemical check of the coolant and say if the head gasket is at fault.
next page
Produced with the support of Green Flag
