IPD sale XeMODeX - Experts in Volvo Electronics
Did you know? 🤔
Logged in users can get email notification of topic replies Log in or register (free).
Amazon Link Buy your stuff using this and it helps MVS!

P80 Burned Valve Discussion Thread - attendant with Data set

Help, Advice and DIY Tutorials on Volvo's extremely popular car line -- Volvo's 1990s "bread and butter" cars -- powered by the ubiquitous and durable Volvo inline 5-cylinder engine.

1992 - 1997 850, 850 R, 850 T5-R, 850 T5, 850 GLT
1997 - 2000 S70, S70 AWD
1997 - 2000 V70, V70 AWD
1997 - 2000 V70-XC
1997 - 2004 C70

User avatar
abscate
MVS Moderator
Posts: 18196
Joined: Sun Feb 17, 2013 5:54 pm
Year and Model: 99T5 ,99S70,2005V70
Location: NYC, ALBANY NY
Has thanked: 200 times
Been thanked: 647 times
Trinidad & Tobago
abscate

P80 Burned Valve Discussion Thread - attendant with Data set

Post by abscate » Fri Feb 05, 2016 9:36 am



Empty Nester
A Captain in a Sea of Estrogen
1999-V70-T5M56 2005-V70-M56 1999-S70 VW T4 BMW

User avatar
greg850r
Posts: 206
Joined: Thu May 03, 2012 5:06 pm
Year and Model: a long list
Location: Mo
Has thanked: 2 times
Been thanked: 8 times
United States of America
greg850r

Re: P80 Burned Valve Discussion Thread - attendant with Data set

Post by greg850r » Mon Mar 04, 2019 10:55 am

burned valve.jpg
I bought a 96 850 Turbo with a burned exhaust valve in #2. Since I got it from the original owner I texted him a list of questions that will hopefully return enough info to make it worth entering in the burned valve database. In the meantime, I have it apart and was wondering; if one had a stack of heads in the barn to rob the valve(s) from. How do I tell the turbo from the non-turbo ones so I don't take an N/A head with me to the machine shop by mistake? It was 3 degrees out there this morning and I don't want to spend a lot of time sorting through them. :x

I got lazy on this one and left the exhaust and turbo all in the car as a unit. When I cracked the head loose I just pulled it forward enough to clear the remaining exhaust studs. I hope to put it back on the same way by using the one piece exhaust gasket that is available (Mahle #MS19361) and trimming one of the ends to fit with a tin snips.

edit: I noticed something about the difference in #2 exhaust port and to a lesser extent the top of the piston that makes me wonder if something went wrong with that injector to cause the problem. Or, could it just be the result of running it with a hole in the valve on that cylinder?
exhaust.jpg
pistons.jpg
You do not have the required permissions to view the files attached to this post.


05 Cross Country wagon
99 C70 Convertible
96 850R wagon
96 850T wagon
96 850 GLT 5spd N/A sedan
97 850R 5spd sedan
66 GTO 421SD 4spd
67 GTO 455 T400
02 Powerstroke 4x4
85 Yota 4x4
24' 454 Challenger
07 Softail Custom
02 Sportster Custom
Parts cars not included

User avatar
abscate
MVS Moderator
Posts: 18196
Joined: Sun Feb 17, 2013 5:54 pm
Year and Model: 99T5 ,99S70,2005V70
Location: NYC, ALBANY NY
Has thanked: 200 times
Been thanked: 647 times
Trinidad & Tobago
abscate

Re: P80 Burned Valve Discussion Thread - attendant with Data set

Post by abscate » Mon Mar 04, 2019 11:50 am

How to tell a bare turbo from a non turbo head?

Crap, I don't know that.

Exhaust valves are sodium filled on turbo - not too helpful.


Empty Nester
A Captain in a Sea of Estrogen
1999-V70-T5M56 2005-V70-M56 1999-S70 VW T4 BMW

User avatar
greg850r
Posts: 206
Joined: Thu May 03, 2012 5:06 pm
Year and Model: a long list
Location: Mo
Has thanked: 2 times
Been thanked: 8 times
United States of America
greg850r

Re: P80 Burned Valve Discussion Thread - attendant with Data set

Post by greg850r » Thu Mar 21, 2019 9:43 pm

I decided to do this head myself instead of sending it out and took all the valves out tonight. The cause of the burned valve was evident as soon as I got the head apart. Several of the other exhaust seats were black in spots, not silver. Black on a valve seat indicates no contact with the valve in that area. Eventually it erodes metal from the valve as hot gasses pass through because the seat in the head has enough mass to dissipate heat and run a little cooler. Carbon build up on the exhaust valve stems prevented them from closing all the way. A clean ring around the valve guide on those show where the hard carbon on the valve stem was crashing into the head when the valve closed thus preventing a good seal at the seat.

My solution is to Run Marvel Mystery oil in my gas to prevent the build up, but buying them used it could be too little too late.


05 Cross Country wagon
99 C70 Convertible
96 850R wagon
96 850T wagon
96 850 GLT 5spd N/A sedan
97 850R 5spd sedan
66 GTO 421SD 4spd
67 GTO 455 T400
02 Powerstroke 4x4
85 Yota 4x4
24' 454 Challenger
07 Softail Custom
02 Sportster Custom
Parts cars not included

tardcart
Posts: 410
Joined: Fri Feb 08, 2019 4:17 pm
Year and Model: 96 850t. 93 940t
Location: Pittstown Nj
Has thanked: 3 times
Been thanked: 37 times
United States of America
tardcart

Re: P80 Burned Valve Discussion Thread - attendant with Data set

Post by tardcart » Fri Mar 22, 2019 4:32 am

it looks like it was running rich or oil entering. You will perhaps find a bad temp sensor or bad thermostat (open) gross vacuum leak, jammed fuel damper slow ox sensor, clogged cat. The na heads have higher lift cams with different part number is one thing to differentiate them. I wonder if the bare casting is the same? I think the higher compression of the NA is from the pistons. If you do have one, use the cams for 10 more hp Ive heard. Adding Mystery oil will only clog the cat and make more carbon.



User avatar
abscate
MVS Moderator
Posts: 18196
Joined: Sun Feb 17, 2013 5:54 pm
Year and Model: 99T5 ,99S70,2005V70
Location: NYC, ALBANY NY
Has thanked: 200 times
Been thanked: 647 times
Trinidad & Tobago
abscate

Re: P80 Burned Valve Discussion Thread - attendant with Data set

Post by abscate » Fri Mar 22, 2019 4:57 am

Closeup for those wondering
You do not have the required permissions to view the files attached to this post.
These users thanked the author abscate for the post:
June


Empty Nester
A Captain in a Sea of Estrogen
1999-V70-T5M56 2005-V70-M56 1999-S70 VW T4 BMW

User avatar
erikv11
Posts: 9169
Joined: Sat Jul 25, 2009 2:03 pm
Year and Model: 850, S/V70, 06 S60R
Location: Iowa
Has thanked: 56 times
Been thanked: 193 times
United States of America
erikv11

Re: P80 Burned Valve Discussion Thread - attendant with Data set

Post by erikv11 » Fri Mar 22, 2019 7:33 am

tardcart wrote:
Fri Mar 22, 2019 4:32 am
I wonder if the bare casting is the same? I think the higher compression of the NA is from the pistons. ...
Yes, same casting, yes it's from the pistons not the head. You can swap heads NA<>turbo the fitment is perfect, however as discussed the turbo head has sodium exhaust valves the NA doesn't so the swap should only go one way, turbo head unto an NA is ok.


'95 854 T5-R, Motronic 4.4, 185k
'96 855 NA, 140k
'98 S70 NA, 210k (living out west)
'98 V70, T5 tune-injectors-turbo, LPT engine, 280k
'06 S60 R, 160k
gone: '96 NA 850 210k, '98 NA V70 182k

User avatar
June
Posts: 1467
Joined: Wed May 04, 2016 11:18 am
Year and Model: 2004 S80 T6
Location: Jacksonville, Florida
Has thanked: 217 times
Been thanked: 112 times
United States of America
June

Re: P80 Burned Valve Discussion Thread - attendant with Data set

Post by June » Fri Mar 22, 2019 7:59 am

Wouldn't the heads be different as the compression ratio is different between turbo and NA? It is my understanding the difference is space volume controlled by depth of valve area of the head? June


My Volvo cars owned
1989 740 GLT ordered
1994 850 4door standard shift ordered
1996 960 ordered
1998 S90 ordered totalled after 3 weeks
1998 V70 GT dealer stock car
2002 S80 T6 ordered totalled
2004 S80 T6 dealer stock car and current car owned

User avatar
erikv11
Posts: 9169
Joined: Sat Jul 25, 2009 2:03 pm
Year and Model: 850, S/V70, 06 S60R
Location: Iowa
Has thanked: 56 times
Been thanked: 193 times
United States of America
erikv11

Re: P80 Burned Valve Discussion Thread - attendant with Data set

Post by erikv11 » Fri Mar 22, 2019 8:37 am

The head castings are identical, the volume difference is achieved by altering the dish in the piston head.

I've done head work but never measured or compared these two, just read a lot over many years from people who (may) have ...


'95 854 T5-R, Motronic 4.4, 185k
'96 855 NA, 140k
'98 S70 NA, 210k (living out west)
'98 V70, T5 tune-injectors-turbo, LPT engine, 280k
'06 S60 R, 160k
gone: '96 NA 850 210k, '98 NA V70 182k

User avatar
abscate
MVS Moderator
Posts: 18196
Joined: Sun Feb 17, 2013 5:54 pm
Year and Model: 99T5 ,99S70,2005V70
Location: NYC, ALBANY NY
Has thanked: 200 times
Been thanked: 647 times
Trinidad & Tobago
abscate

Re: P80 Burned Valve Discussion Thread - attendant with Data set

Post by abscate » Fri Mar 22, 2019 8:56 am

erikv11 wrote:
Fri Mar 22, 2019 7:33 am
tardcart wrote:
Fri Mar 22, 2019 4:32 am
I wonder if the bare casting is the same? I think the higher compression of the NA is from the pistons. ...
Yes, same casting, yes it's from the pistons not the head. You can swap heads NA<>turbo the fitment is perfect, however as discussed the turbo head has sodium exhaust valves the NA doesn't so the swap should only go one way, turbo head unto an NA is ok.

Those Volvo Turbo exhaust valves with Sodium (not NA :D ) are a scant $85 each by the way - thats $850 in valves if you replace them all.

9454610


Empty Nester
A Captain in a Sea of Estrogen
1999-V70-T5M56 2005-V70-M56 1999-S70 VW T4 BMW

Post Reply