1.8T Still not starting - Page 4

Aitchbee · 24th October 2009, 11:21

Hi Again,

I still think there`s a possibility that the cambelt slipped a tooth and could cause the problems you see.In Theory :

I don`t know how many teeth are on the crankshaft pulley,but if there were,let`s say,24,then that would mean that the piston(s) in relation to the valves would be retarded by 15 deg.Put another way the valves opening and closing advanced by approx 7.5 deg.
This means that when on the exhaust stroke,the exhaust valves would close approx 6.5 deg before TDC (rather than approx 1 deg after) and,perhaps more importantly,the inlets open approx 8.5 deg BTDC,which would cause the piston to `push`the exhaust gases through the inlet valve and cause,what? A bit of a cough and splutter methinks.(Pressurization of crankcase etc)
I don`t think the slipping of one tooth would mean the pistons hitting the (inlet)valves, 2 teeth maybe...My Audi survived it.

Your `misfire on no 4 cyl` could have been a dodgy plug,before your service?Again,this happened to me.

I would check the valve timing using the `valve overlap` method,which saves the hassle of getting at timing marks.

aitchbee

Rovernut · 24th October 2009, 12:00

I have an occasional missfire under load on my 1.8T. I'm told its caused by a corroded terminal on a coil pack as before it was cleaned up the missfire was on tickover.

Are you sure you have a good spark under compression? Check your coils.

this engine runs fairly well with one cambelt tooth out!

T-Cut · 24th October 2009, 12:05

Nobody's yet explained the crankcase pressurisation. I think that the most significant factor so far.

TC

Gary · 24th October 2009, 12:05

Quote:

Originally Posted by Aitchbee

Hi Again,

I still think there`s a possibility that the cambelt slipped a tooth and could cause the problems you see.In Theory :

I don`t know how many teeth are on the crankshaft pulley,but if there were,let`s say,24,then that would mean that the piston(s) in relation to the valves would be retarded by 15 deg.Put another way the valves opening and closing advanced by approx 7.5 deg.
This means that when on the exhaust stroke,the exhaust valves would close approx 6.5 deg before TDC (rather than approx 1 deg after) and,perhaps more importantly,the inlets open approx 8.5 deg BTDC,which would cause the piston to `push`the exhaust gases through the inlet valve and cause,what? A bit of a cough and splutter methinks.(Pressurization of crankcase etc)
I don`t think the slipping of one tooth would mean the pistons hitting the (inlet)valves, 2 teeth maybe...My Audi survived it.

Your `misfire on no 4 cyl` could have been a dodgy plug,before your service?Again,this happened to me.

I would check the valve timing using the `valve overlap` method,which saves the hassle of getting at timing marks.

aitchbee

The continuing saga………..I have checked the cam timing and that is all okay (It would have been helpful if whoever designed the car put an inspection hole in the bulkhead which would have made it easies to see the bottom pulley marks).

The pipe from the cam cover actually goes to the air intake for the turbo and not the turbo itself. I also noticed that there is a small black tube from the air filter which connects down the turbo area is also off????.....If it is the turbo oil seals – would this stop the car from starting?

Regards
Gary

Aitchbee · 24th October 2009, 12:30

Well that`s blown my theory about slipped cambelt!

It`s starting to look like the turbo is involved.Silly question,but have you had a look at your plugs?See if they are oiled up.

This can give you some ideas about what can go wrong with the turbo,which I know little about,except the theory on how it works.
http://www.midlandturbo.com/faultfinding.php#top
It is obviously interconnected with the engine breathing system.

I can`t understand how your compressions are so low though.According to Haynes,they should be uniformly around 10 bar,twice what you have.

Aitchbee

Gary · 24th October 2009, 13:04

Quote:

Originally Posted by Aitchbee

Well that`s blown my theory about slipped cambelt!

It`s starting to look like the turbo is involved.Silly question,but have you had a look at your plugs?See if they are oiled up.

This can give you some ideas about what can go wrong with the turbo,which I know little about,except the theory on how it works.
http://www.midlandturbo.com/faultfinding.php#top
It is obviously interconnected with the engine breathing system.

I can`t understand how your compressions are so low though.According to Haynes,they should be uniformly around 10 bar,twice what you have.

Aitchbee

I think your theory about the cam belt was a good one and well worth trying although it looks like T Cut is on the right track. THE BAD NEWS I have just taken the air induction pipe off the turbo and there is a fair amount of new engine oil in there and there is also engine oil in the inlet manifold so it looks as though something has gone wrong in the turbo. It would appear engine oil has been sucked in to the engine from the turbo via the inlet manifold. What damage if any would this have done to the engine?

T-Cut · 24th October 2009, 14:27

Seems like the turbo oil seals have failed as a starter to the diagnosis. If that's all it is, it doubt any mechanical damage to the engine. The turbo itself may be damaged, as well as the catalyst, but that's secondary ATM. Starting isn't dependent on the turbo, but any oil around the ignition system/plugs won't help. As suggested Aitchbee, check the plugs for oil contamination. Maybe we're finally getting somewhere.

TC

Rovernut · 24th October 2009, 14:56

And possibly HT lead tracking preventing engine from starting?

Injectors could be damaged through engine oil contamination?

Ratdogfink · 24th October 2009, 18:22

Mine will run without the turbo!! I know as I blew a the inlet pipe off once!! The car was fine just like a non turbo 1.8.
How did you get to the end of the crank to check the cam timing?
You need to have all turbo boost control pipes in place. Trace them all and check they are in place.
The cam to inlet pipe could have been blown off due to overboost as the one way valve lets air from engine to inlet not inlet to engine. Or very high pressure in bottom end should not blow the pipe off.

Gary · 25th October 2009, 14:44

Well I have spent the morning cleaning everything up and it’s trying to start now. What it’s doing is pumping white smoke from the turbo air induction pipe into the air filter box. The battery is a bit weak now aswell so not turning over very fast.

24th October 2009, 12:00	#32
Rovernut Loves to post R75 Conn Tourer, R8 Tourer, R8 Cabby Join Date: Nov 2006 Location: Manchester Posts: 401 Thanks: 87 Thanked 11 Times in 7 Posts	I have an occasional missfire under load on my 1.8T. I'm told its caused by a corroded terminal on a coil pack as before it was cleaned up the missfire was on tickover. Are you sure you have a good spark under compression? Check your coils. this engine runs fairly well with one cambelt tooth out! __________________ Wonderful Wedgwood Turbo Towcar

24th October 2009, 14:56	#38
Rovernut Loves to post R75 Conn Tourer, R8 Tourer, R8 Cabby Join Date: Nov 2006 Location: Manchester Posts: 401 Thanks: 87 Thanked 11 Times in 7 Posts	And possibly HT lead tracking preventing engine from starting? Injectors could be damaged through engine oil contamination? __________________ Wonderful Wedgwood Turbo Towcar

24th October 2009, 18:22	#39
Ratdogfink Loves to post 1 Join Date: Jan 2007 Location: 1 Posts: 336 Thanks: 0 Thanked 0 Times in 0 Posts	Mine will run without the turbo!! I know as I blew a the inlet pipe off once!! The car was fine just like a non turbo 1.8. How did you get to the end of the crank to check the cam timing? You need to have all turbo boost control pipes in place. Trace them all and check they are in place. The cam to inlet pipe could have been blown off due to overboost as the one way valve lets air from engine to inlet not inlet to engine. Or very high pressure in bottom end should not blow the pipe off. Last edited by Ratdogfink; 24th October 2009 at 18:24..

24th October 2009, 11:21	#31
Aitchbee Newbie Rover 75 1.8t Club SE Join Date: Aug 2009 Location: DUMFRIES Posts: 24 Thanks: 0 Thanked 0 Times in 0 Posts	Hi Again, I still think there`s a possibility that the cambelt slipped a tooth and could cause the problems you see.In Theory : I don`t know how many teeth are on the crankshaft pulley,but if there were,let`s say,24,then that would mean that the piston(s) in relation to the valves would be retarded by 15 deg.Put another way the valves opening and closing advanced by approx 7.5 deg. This means that when on the exhaust stroke,the exhaust valves would close approx 6.5 deg before TDC (rather than approx 1 deg after) and,perhaps more importantly,the inlets open approx 8.5 deg BTDC,which would cause the piston to `push`the exhaust gases through the inlet valve and cause,what? A bit of a cough and splutter methinks.(Pressurization of crankcase etc) I don`t think the slipping of one tooth would mean the pistons hitting the (inlet)valves, 2 teeth maybe...My Audi survived it. Your `misfire on no 4 cyl` could have been a dodgy plug,before your service?Again,this happened to me. I would check the valve timing using the `valve overlap` method,which saves the hassle of getting at timing marks. aitchbee

24th October 2009, 12:05	#33
T-Cut This is my second home Rover75 and Mreg Corsa. Join Date: Nov 2006 Location: Sumweer onat mote o'dust (Sagin) Posts: 21,753 Thanks: 341 Thanked 3,660 Times in 2,924 Posts	Nobody's yet explained the crankcase pressurisation. I think that the most significant factor so far. TC

24th October 2009, 12:30	#35
Aitchbee Newbie Rover 75 1.8t Club SE Join Date: Aug 2009 Location: DUMFRIES Posts: 24 Thanks: 0 Thanked 0 Times in 0 Posts	Well that`s blown my theory about slipped cambelt! It`s starting to look like the turbo is involved.Silly question,but have you had a look at your plugs?See if they are oiled up. This can give you some ideas about what can go wrong with the turbo,which I know little about,except the theory on how it works. http://www.midlandturbo.com/faultfinding.php#top It is obviously interconnected with the engine breathing system. I can`t understand how your compressions are so low though.According to Haynes,they should be uniformly around 10 bar,twice what you have. Aitchbee

24th October 2009, 14:27	#37
T-Cut This is my second home Rover75 and Mreg Corsa. Join Date: Nov 2006 Location: Sumweer onat mote o'dust (Sagin) Posts: 21,753 Thanks: 341 Thanked 3,660 Times in 2,924 Posts	Seems like the turbo oil seals have failed as a starter to the diagnosis. If that's all it is, it doubt any mechanical damage to the engine. The turbo itself may be damaged, as well as the catalyst, but that's secondary ATM. Starting isn't dependent on the turbo, but any oil around the ignition system/plugs won't help. As suggested Aitchbee, check the plugs for oil contamination. Maybe we're finally getting somewhere. TC

25th October 2009, 14:44	#40
Gary Avid contributor Rover 75 1.8T Club - Mitsubishi GTO Join Date: Apr 2009 Location: Weymouth Posts: 107 Thanks: 0 Thanked 0 Times in 0 Posts	Well I have spent the morning cleaning everything up and it’s trying to start now. What it’s doing is pumping white smoke from the turbo air induction pipe into the air filter box. The battery is a bit weak now aswell so not turning over very fast.