Engine runs lumpy

Anadinolin · Jul 5th, 2015, 09:28

Hiya guys,

My engine has been running lumpy. Im not sure what it could be. It's tappety with 5w30 (need to double check) castrol oil for high mileage motors in there and sounds like it only runs on 3 cylinders. The sound doesn't change when I unplug each of the spark plugs one by one. The exhaust gasket had blown on cylinder 2 and 4, so I changed that. It's also rich.

I cannot think of anything else at the moment that would solve the problem. I am thinking now that the timing is off. Any of you guys got ideas on where to point me?

doingitsideways · Jul 5th, 2015, 12:12

Air leak would be my best guess, Andrew.
Try spraying all around the intake hoses and manifolds/SPI joint with carb cleaner with the engine running and listen for changes.

Also, get that oil out as it's far too thin. 10w40 for these old girls.
(Don't forget they were designed LONG before exotic oils like that were around

Anadinolin · Jul 19th, 2015, 18:48

It tried the carb cleaner round the single point and the exhaust sections, with no change in engine note. I have also tried 10w40 as you suggested, it quietened a little bit, but still noisy and the spark plug in cylinder 2 has carboned up....puzzled :/

doingitsideways · Jul 19th, 2015, 19:58

Misfire on that cylinder then.

Compression test next, change the plugs around and keep an eye on it.
Also HT leads, clean dizzy cap etc.

volvo for ever · Jan 10th, 2016, 13:03

they were bad for manilfold gaskets leaking as well as downpipe seal leaking ,,,,you need to check bascis dist cap center bush and rotor arm,,spak plugs,also 2x vacumm hoses on spi unit they were bad for colapsing inside pipe causing starting running faults

regards

Anadinolin · Jan 11th, 2016, 12:28

It was a warped inlet/exhaust manifold and down a cylinder in the end. i still need to crack open the block to see if the issue was a cracked cylinder or a burnt valve.

- nice thread revival though :P

Jul 5th, 2015, 09:28	#1
Anadinolin VOC Member Last Online: Jun 20th, 2022 14:32 Join Date: Oct 2009 Location: Upminster View Photos By: Anadinolin	Engine runs lumpy Hiya guys, My engine has been running lumpy. Im not sure what it could be. It's tappety with 5w30 (need to double check) castrol oil for high mileage motors in there and sounds like it only runs on 3 cylinders. The sound doesn't change when I unplug each of the spark plugs one by one. The exhaust gasket had blown on cylinder 2 and 4, so I changed that. It's also rich. I cannot think of anything else at the moment that would solve the problem. I am thinking now that the timing is off. Any of you guys got ideas on where to point me? __________________ what good music deserves is full deep bass to give it warmth. the stock volvo sub works....just at high volumes Drum n Bass and dubstep

Jul 5th, 2015, 12:12	#2
doingitsideways The Daddy Last Online: Feb 29th, 2024 15:07 Join Date: May 2010 Location: Manchester	Air leak would be my best guess, Andrew. Try spraying all around the intake hoses and manifolds/SPI joint with carb cleaner with the engine running and listen for changes. Also, get that oil out as it's far too thin. 10w40 for these old girls. (Don't forget they were designed LONG before exotic oils like that were around __________________ XC90 V8 Exec, C70 2.4T Convertible, S70 T5 CD, 850 TDI, 2 x Escort vans and a 2.8i Capri. Clearout has begun, but must continue!

Jul 19th, 2015, 18:48	#3
Anadinolin VOC Member Last Online: Jun 20th, 2022 14:32 Join Date: Oct 2009 Location: Upminster View Photos By: Anadinolin	It tried the carb cleaner round the single point and the exhaust sections, with no change in engine note. I have also tried 10w40 as you suggested, it quietened a little bit, but still noisy and the spark plug in cylinder 2 has carboned up....puzzled :/ __________________ what good music deserves is full deep bass to give it warmth. the stock volvo sub works....just at high volumes Drum n Bass and dubstep

Jul 19th, 2015, 19:58	#4
doingitsideways The Daddy Last Online: Feb 29th, 2024 15:07 Join Date: May 2010 Location: Manchester	Misfire on that cylinder then. Compression test next, change the plugs around and keep an eye on it. Also HT leads, clean dizzy cap etc. __________________ XC90 V8 Exec, C70 2.4T Convertible, S70 T5 CD, 850 TDI, 2 x Escort vans and a 2.8i Capri. Clearout has begun, but must continue!

Jan 11th, 2016, 12:28	#6
Anadinolin VOC Member Last Online: Jun 20th, 2022 14:32 Join Date: Oct 2009 Location: Upminster View Photos By: Anadinolin	It was a warped inlet/exhaust manifold and down a cylinder in the end. i still need to crack open the block to see if the issue was a cracked cylinder or a burnt valve. - nice thread revival though :P __________________ what good music deserves is full deep bass to give it warmth. the stock volvo sub works....just at high volumes Drum n Bass and dubstep

Jan 10th, 2016, 13:03	#5
volvo for ever Premier Member Last Online: Feb 4th, 2023 15:10 Join Date: Apr 2015 Location: uk	they were bad for manilfold gaskets leaking as well as downpipe seal leaking ,,,,you need to check bascis dist cap center bush and rotor arm,,spak plugs,also 2x vacumm hoses on spi unit they were bad for colapsing inside pipe causing starting running faults regards

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