LPG Issues After Engine Swap on S70 – Need Spark Plug Advice

perhss70 · Post by **perhss70** » 24 Sep 2024, 01:58

Hi all,
I posted about this in the summer but still need some advice.
I’ve been struggling with my S70 after an engine swap (due to overheating from a gasket breach). The car feels off below 2,800–3,000 RPM, but only when running on LPG and only after about 10 minutes of driving. I suspect it’s the spark plugs.
The Volvo plug (#30637308) is pricey (90 EUR), and NGK suggests their equivalent is NGK 3500. However, I've heard colder plugs might be better for LPG. I found Bosch FR5KI332S and Denso IK22 at around 10 EUR each and wanted to know if anyone has experience with them.
Also, would it be an issue to switch to nickel plugs like NGK BKR7E and change them more often to save costs?
Any insights or recommendations would be greatly appreciated!

Post by **scot850** » 24 Sep 2024, 10:25

There are still advocates for the base Bosch copper plugs as we call them. Changing them more frequently being the only issue.

Unfortunately on this side of the Atlantic, there are few if any Volvos that run LPG. That is a Euro mainly thing, particularly in UK.

Have you tried talking to any of the LPG installers or equipment suppliers to see if they can add any information to this in terms if colder plugs will help. It may well be a balancing act trying to find a compromise that works with both. Just to confirm, your car is a non-turbo (NA) S70 and still had the distributor?

Neil.

perhss70 · Post by **perhss70** » 25 Sep 2024, 04:28

scot850 wrote: ↑24 Sep 2024, 10:25 There are still advocates for the base Bosch copper plugs as we call them. Changing them more frequently being the only issue.

Unfortunately on this side of the Atlantic, there are few if any Volvos that run LPG. That is a Euro mainly thing, particularly in UK.

Have you tried talking to any of the LPG installers or equipment suppliers to see if they can add any information to this in terms if colder plugs will help. It may well be a balancing act trying to find a compromise that works with both. Just to confirm, your car is a non-turbo (NA) S70 and still had the distributor?

Neil.

Forgot to mention since my car model is in my signature. i have a 1997 S70 2.0T (B5204T3) and yes it has a distributor