Engine: 850 T5/R - Spark plug cover

dahamsta · Aug 3rd, 2020, 23:03

Tidying up my engine compartment, I noticed that my spark plug cover waggles about a bit if pushed, despite new bolts. Are there supposed to be washers under the bolts, or perhaps a gasket under the cover? I don't see either in VIDA. Or is it just loose fit?

Cookeh · Aug 4th, 2020, 09:00

No washer, no gasket. Still shouldn't wobble significantly though, should be held fairly tightly in place by the bolts.

RollingThunder · Aug 4th, 2020, 09:08

As Cookeh says, its a loose fit with no gasket. It shouldn't wobble about though - both are flat surfaces.

Make sure that the seating surfaces are clean. Also make sure that the plastic block where the HT leads pass through, and the ridge in the PCV oil breather pipe are sitting correctly. Either of those will prevent the cover plate from sitting snugly.

Cookeh · Aug 4th, 2020, 10:14

Quote:

Originally Posted by RollingThunder

Also make sure that the plastic block where the HT leads pass through, [...] are sitting correctly. Either of those will prevent the cover plate from sitting snugly.

That's an excellent point. When I replaced my leads the block was a smidge larger than OE Volvo (despite being Bougicord!), and I had to make sure it was positioned just so in order to get the cover on properly.

dahamsta · Aug 5th, 2020, 00:06

Thanks folks. I think that would make it too tight rather than loose, but I did notice that the PCV hose wasn't as straight as it could be, I'll check that.

ASt85 · Aug 5th, 2020, 16:54

Quote:

Originally Posted by dahamsta

Tidying up my engine compartment, I noticed that my spark plug cover waggles about a bit if pushed, despite new bolts. Are there supposed to be washers under the bolts, or perhaps a gasket under the cover? I don't see either in VIDA. Or is it just loose fit?

Check that the bolts are clean and clear and that there's no muck down the thread holes - the torx should hand tighten down fully at around 5 to 7Nm with no wobble or slack - if the threads are crusty, dry or corroded you get that slack.

tc · Aug 8th, 2020, 19:54

Sometimes the recessed mounting holes fracture and break loose maybe that's why its moving around so much?

Aug 3rd, 2020, 23:03	#1
dahamsta Member Last Online: Yesterday 23:58 Join Date: Mar 2012 Location: Ireland	Spark plug cover Tidying up my engine compartment, I noticed that my spark plug cover waggles about a bit if pushed, despite new bolts. Are there supposed to be washers under the bolts, or perhaps a gasket under the cover? I don't see either in VIDA. Or is it just loose fit?

Aug 4th, 2020, 09:00	#2
Cookeh Premier Member Last Online: Sep 14th, 2022 17:04 Join Date: Jan 2018 Location: Derbyshire	No washer, no gasket. Still shouldn't wobble significantly though, should be held fairly tightly in place by the bolts. __________________ 1995 Volvo 850 T5 Estate (Manual)

Aug 4th, 2020, 09:08	#3
RollingThunder Grumpy Old Git Last Online: Apr 16th, 2024 10:24 Join Date: Dec 2004 Location: South Yorkshire View Photos By: RollingThunder	As Cookeh says, its a loose fit with no gasket. It shouldn't wobble about though - both are flat surfaces. Make sure that the seating surfaces are clean. Also make sure that the plastic block where the HT leads pass through, and the ridge in the PCV oil breather pipe are sitting correctly. Either of those will prevent the cover plate from sitting snugly. __________________ S40 2.4i '07 Japanese import '96 850R - https://www.volvoforums.org.uk/showthread.php?t=312484 Ex Danish Embassy '96 940 GLE LPT - https://www.volvoforums.org.uk/showthread.php?t=326071

Aug 5th, 2020, 00:06	#5
dahamsta Member Last Online: Yesterday 23:58 Join Date: Mar 2012 Location: Ireland	Thanks folks. I think that would make it too tight rather than loose, but I did notice that the PCV hose wasn't as straight as it could be, I'll check that.

Aug 8th, 2020, 19:54	#7
tc VOC Member Last Online: Jan 5th, 2024 15:51 Join Date: Dec 2004 Location: Chorley View Photos By: tc	Sometimes the recessed mounting holes fracture and break loose maybe that's why its moving around so much?

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