Login Register

Overboosting?

Help, Advice and DIY Tutorials on Volvo's P80 platform cars -- Volvo's 1990s "bread and butter" cars -- powered by the ubiquitous and durable Volvo inline 5-cylinder engine.

1992 - 1997 850, including 850 R, 850 T-5R, 850 T-5, 850 GLT
1997 - 2000 S70, S70 AWD
1997 - 2000 V70, V70 AWD
1997 - 2000 V70-XC
1997 - 2004 C70

Post Reply
wotnartd
Posts: 35
Joined: 10 July 2014
Year and Model: 1998 V70 xc
Location: Wisconsin

Overboosting?

Post by wotnartd »

Hey folks, so I did some fiddling, and things happened. Last week I changed my TCV hoses over to silicone and tightened the wastegate a touch. Was boosting all the way to 5 psi. And today I just put a few clamps where I had run out, had to disconnect and reconnect a few things, but nothing major. All the sudden, 10 psi.

Motor's too hot, and it's too dark to really do anything. I don't know, kinda concerned about the boost. Should probably address it.

What have you all had like this?

JDS60R
MVS Moderator
Posts: 3532
Joined: 21 February 2009
Year and Model: 2007 S60R 2016 XC70
Location: Mount Juliet, TN
Been thanked: 3 times

Post by JDS60R »

Recheck the electrical and hose connections to the tcv. Then return wastegate to stock position
Retired

User avatar
abscate  
MVS Moderator
Posts: 35288
Joined: 17 February 2013
Year and Model: 99: V70s S70s,05 V70
Location: Port Jefferson Long Island NY
Has thanked: 1502 times
Been thanked: 3817 times

Post by abscate »

A waste gate adjustments is a subtle thing like a 1/4to 1/2 turn at a time.

You can bend a connecting rod if you get " enthusiastic"
Empty Nester
A Captain in a Sea of Estrogen
1999-V70-T5M56 2005-V70-M56 1999-S70 VW T4 XC90-in-Red
Link to Maintenance record thread

mecheng
Posts: 1271
Joined: 27 March 2014
Year and Model: 1998 Volvo S70 T5
Location: Ontario, Canada
Has thanked: 15 times
Been thanked: 21 times

Post by mecheng »

You can only turn the waste gate in 1/2 increments, so start with 1/2 first.

Most people don't go beyond 1 turn, with the HPT. With the LPT, most don't adjust it at all.
1998 Volvo S70 T5 - SE - 240km - Sold July 2018
1997 Volvo 850 GLT - 190km
Boost is my drug of choice

wotnartd
Posts: 35
Joined: 10 July 2014
Year and Model: 1998 V70 xc
Location: Wisconsin

Post by wotnartd »

I was using a pressure gauge to dial it in. Was opening at 5.

This morning, I took a quick peek, verified everything was connected, it was. It hit 10, popped a P0243 code, and then about 15 minutes later was back to boosting to 5.

I'm going to double check the connections on the TCV and ohm it out on lunch, and turn the wastegate back 1 full turn. And once more when I get home check everything again.

I'm thinking maybe the compressor line to the TCV might not be quite right and that's one of the hoses that I had clamped, last night. It would make sense, if it were constricted, that I could overboost.

wotnartd
Posts: 35
Joined: 10 July 2014
Year and Model: 1998 V70 xc
Location: Wisconsin

Post by wotnartd »

Rechecked all the hoses, connections and plugs. All good. Verified the wastegate is opening at 4 psi, it is.

Still overboosting.

wotnartd
Posts: 35
Joined: 10 July 2014
Year and Model: 1998 V70 xc
Location: Wisconsin

Post by wotnartd »

Holy cow, guys. I'm a big dope.

I must have adjusted the WG under some pressure! When I pulled the rod off the gate, it probably retracted 1/4". I'm still feeling something is amiss, but hey, the TCV is still good!

Atis
Posts: 105
Joined: 20 April 2013
Year and Model: S70 GLT 1998
Location: Hungary
Has thanked: 1 time
Been thanked: 4 times

Post by Atis »

The WG setup is around 0.125 to 0.2 bar depending on the engine you have (there is an fcp or ipd video on youtube where you can find the proper value). The TCV (I mean ECU) is learning quite fast so it is adapting to the new setup to protect the engine. So the best should be the factory setup or somewhere near.

Bowtiekilla02
Posts: 5
Joined: 21 July 2015
Year and Model: 1996
Location: United states

Post by Bowtiekilla02 »

Make sure all lines that you replaced are as short as they can be to the compressor housing to the wastegate and intake tube. If you have them too long the tcv will not be able to open and close at a effeciante rate cause over boost and spikes. That's what happened to me when I changed my hoses cause I didn't pay attention and left the one to the compressor housing to long.

wjhandy850
Posts: 128
Joined: 12 October 2009
Year and Model: 854 GLT 1997
Location: Ga

Post by wjhandy850 »

We need to get to official lengths for those hoses. I am sure there are many out there running with the wrong lengths.

Post Reply
  • Similar Topics
    Replies
    Views
    Last post