Mazda 6 Diesel Sport 2L 2002 model - ENGINE STALLING THEN KNOCKING SOUND PLEASE HELP

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Sun 16 Jan 2011 15:14
Mazda 6 Diesel Sport 2L 2002 model - ENGINE STALLING THEN KNOCKING SOUND PLEASE HELP - wrxmatt

Hi, I have a 2002 Mazda 6 136bhp deisel sport. Its done 75000 miles with full service history and a recent cam belt change. The engine has recently failed on me and the car is now stuck on my driveway and i don't know what to do. Here is what has happened.

I have had the car over 6 months now. In all this time it seems to have been running ok but has been burning oil (about half a litre every 2-3 weeks). There has been no sign of water in the oil or the other way round. It wasn;t smoking other than on full throttle then black smoke could be seen behind the car.

The other night i was driving hime and it stalled at traffic lights. I restarted it which took a few cranks and drove on about 300 metres. I could now hear a reasonably loud knocking/tapping noise from the engine which increased in volume and speed when accelerating. I was looking to pull over at the next opportunity but it cut out when moving. I stopped and attempted to restart but it just turned over.

I looked at the dipstick and the oil was not registering on it, i could see none leaking from anywhere and the coolant level was fine with no signs of oil in it. I took off the oil filler cap and there was a small amount of white smoke coming from inside the engine. There was no gunk on the filler cap. I topped up the oil and it only needed about 1 and a half litres until full on the dipstick again.

I attempted starting the car again and it ran roughly, there was again a loud knocking/tapping from what appeared to be the top part of the engine. I could also see white smoke coming from under the plastic engine cover in the area of the top right side of the engine block (as looking from the front of the car).

I have since started the car with the plastic engine cover removed. It starts first time and runs but roughly and shakes a bit. As looking at the engine block from the front of the car i can see the following:

The two right hand metal discs on the top of the engine which house the injectors bounce up and down slightly in time with the knocking/tapping noise. Also below them on the front of the engine block are two connectors with metal pipes coming from them (possibly the exhaust gas pipes. Again as it is running these bounce in and out slightly. This only happens on the two right hand ones, the left hand side of the engine seems fine. White smoke also leaks from the above mentioned parts.
I have no idea what is wrong and the car is not drivable. Does anyone have a clue what these symptoms are?


Many thanks
Matt

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Sun 16 Jan 2011 23:30
Mazda 6 Diesel Sport 2L 2002 model - ENGINE STALLING THEN KNOCKING SOUND PLEASE HELP - bathtub tom

>>I looked at the dipstick and the oil was not registering on it, i could see none leaking from anywhere and the coolant level was fine with no signs of oil in it. I took off the oil filler cap and there was a small amount of white smoke coming from inside the engine. There was no gunk on the filler cap. I topped up the oil and it only needed about 1 and a half litres until full on the dipstick again.

So, you've ignored all the other signs that say you haven't done the usual driver checks !

When did you last check the dip dipstick?

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Mon 17 Jan 2011 18:24
Mazda 6 Diesel Sport 2L 2002 model - ENGINE STALLING THEN KNOCKING SOUND PLEASE HELP - wrxmatt

It was checked the day before and was fine. Because it has been using oil i was checking it every few days and topping up if necessary.

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Mon 17 Jan 2011 18:30
Mazda 6 Diesel Sport 2L 2002 model - ENGINE STALLING THEN KNOCKING SOUND PLEASE HELP - Peter D

You need to have the diagnostics run . It could be a jams hydraulic cam follower a failed injector or in fact a head gaster leaking between two adjacent cylinders. Regards Peter

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Mon 17 Jan 2011 18:44
Mazda 6 Diesel Sport 2L 2002 model - ENGINE STALLING THEN KNOCKING SOUND PLEASE HELP - wrxmatt

Thanks Peter, i did think about the head gasket but there is no water in the oil, oil in water and coolant level remains fine.

It just appears to me that there is too much pressure in the 3rd and 4th cylinders and gas is leaking out of the seals round the injectors and fuel injection pipes. The tapping sound could be this gas escaping.

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Mon 17 Jan 2011 19:27
Mazda 6 Diesel Sport 2L 2002 model - ENGINE STALLING THEN KNOCKING SOUND PLEASE HELP - Peter D

A leaking HG does not always leak water into the oil or visa versa. Leaking around the injectors is strange. Is this engine a direct injector common rail injector or a pump and distributor with metal pipes. Regards Peter

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Mon 17 Jan 2011 19:36
Mazda 6 Diesel Sport 2L 2002 model - ENGINE STALLING THEN KNOCKING SOUND PLEASE HELP - Peter D

I have read your post again and I'm starting to think your new timing belt has jump so you timing is all over the place. I would not run the engine again until at least the timing is checked. Regards Peter

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Mon 17 Jan 2011 19:58
Mazda 6 Diesel Sport 2L 2002 model - ENGINE STALLING THEN KNOCKING SOUND PLEASE HELP - Peter D

If this is a distributor type diesel then the two leaking injectors may have come loose and the compression pressure is not getting high enough to ignite the diesel. How much gas is leaking out of them, is it just a seap or is it relly blowing out. Regards Peter

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Mon 17 Jan 2011 20:10
Mazda 6 Diesel Sport 2L 2002 model - ENGINE STALLING THEN KNOCKING SOUND PLEASE HELP - wrxmatt

From looking at engine diagrams it has a common rail which sits on the front of the engine, there are 4 metal pipes from this which run into the front side of the block where each cylinder is, it is the 3rd and 4th ones of these that also bounce in and out and a slight bit of white gas leaks from them.

On the top of the engine are 4 injectors with wires and rubber pipes running to them. These each sit in a round metal disc with a seal around each one. Again the 3rd and 4th ones bounce up and down and again a small amount of white gas leaks from the seals. There is also a small amount of oil seeping from these same two seals.

Thanks for your help, its much appreciated.

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Mon 17 Jan 2011 20:15
Mazda 6 Diesel Sport 2L 2002 model - ENGINE STALLING THEN KNOCKING SOUND PLEASE HELP - wrxmatt

Sorry i think the 4 things i said were injectors on top of the engine are injector nozzles.

I did consider the timing slipping but wouldn;t this effect the 1st and 2nd cylinders too?

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Mon 17 Jan 2011 20:30
Mazda 6 Diesel Sport 2L 2002 model - ENGINE STALLING THEN KNOCKING SOUND PLEASE HELP - Peter D

There should be a common rail which is mounted above all four injectors. This rail is fed with high pressure fuel forma pump. There is an electrical connectio to each injector and they should not be moving around. Regards Peter

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Mon 17 Jan 2011 20:49
Mazda 6 Diesel Sport 2L 2002 model - ENGINE STALLING THEN KNOCKING SOUND PLEASE HELP - wrxmatt

The common rail on this is mounted below the injector pipes, it has a pump mounted on the end of the common rail. The injector nozzles are seperate on the top of the engine and have the wires going to them. It is only these bits on the 3rd and 4th cylinders that move and gas leaks from so its just the right side of the engine affected.

Would the engine still run if the timing has slipped and would it just affect two cylinders?

Also th engine check light does not come on so its not indicating a problem.

I know i should take it to a garage but the car has caused me so many problems and cost me loads on repairs so i'm not wanting to waste more cash if i'm going to end up scrapping it. Also its not drivable and is at home so getting it to a garage is difficult. If i have a rough idea of potential problems then i can assess whether to risk it going to a garage.

Many thanks

Matt

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