My S40 has been garaged for ten years with a blown turbo. My son sourced a second hand t4 turbo and installed in the car. The car has almost no power. I can drive it around at 20km/hr but struggled to go up a small hill or even get up the car ramps. The catalytic converter got so hot the the carpet etc in the car started smoking and melting. There are no errors on the OBD/ECU. (I did have coil/misfire errors but the plastic plugs were not seating properly to the coils and I fixed that and reset ECU. I'm not a mechanic but am happy to give anything a go. There was no boost showing up on OBD and I couldn't hear the turbo spool.I checked the 'new' turbo and it was shot so I rebuilt it and put it back in car. Turbo now spools and get boost on OBD but car symptoms are the same. No power, overheating Cat (I didn't let it get too hot but my inexperienced eye tells me it's getting too hot too quick - can't hold finger on interior floor of car). I am supprised that I am getting no errors on the OBD. Any ideas what I should attack first? What could be wrong that wouldn't cause an ECU error? I also did the PCB system while I was under the bonnet. Not sure if it's normal for this car but it splashes a lot of oil out if you open the oil cap while running. I don't get that on my 2.5T but that does have some angled flanges under the cap that look like they are there to stop oil splashing. Any advice appreciated. Want to get the car back on the road for my son. Thanks

Where to start?

I'd start with a compression test, that will tell a lot.
Carefully check and/or replace the old vacuum lines, and check for air leaks at the intake.
I wonder about the timing belt and valve timing, also if the timing belt can go west with age?

Other's should chime in soon.

Good luck, Bill

Fixed! 'ish. Compression 150 on second crank. Catalytic converter all good. Plugs bad replaced them. Not firing on cylinder 1 and 2 so put spare coils in. Still not firing but have spark. Swapped injectors on 1 and 2 with no change... Double checked and realised the leads for cyl 1 and 2 where swapped over and now the car is running. I'm supprised that didn't cause any errors. Only issue now is that I can't seem to clear the ECU errors. There are circuit errors on all four injectors from when I was testing and one for each of the O2 sensors which where unplugged when I took the Cat out. I have a Bluetooth one and use torque pro and never had a problem clearing errors. I'm leaving the battery unplugged overnight and will see what that does. I find it hard too believe I have hard errors on the injectors and o2 Car is still a bit sluggish but assuming that's old fuel and/or engine responding to errors. Any ideas let me know. Otherwise I'll post an update.

Whats your name?

With the funky injector behavior, look for a missing or loose ground to the cylinder head.

Bill

Thanks. Will do. Richard.

How in the heck did you manage to get the coil leads swapped? Yes, that will send raw fuel into the cat and cause it to overheat! It's a good thing you didn't have to call the fire department.

As for ECU errors, unplugging the battery for 15 minutes should clear everything.

You will want to recheck the plug connectors for the O2 sensors, clean them and make sure the male leads didn't get pushed back.

Gasoline really doesn't get 'old'. What you get is water and sludge, the latter plugging up the injectors. Remember, the bad stuff is on the bottom of the tank and gets picked up first.

How did you test the injectors? Pull the rail, put a cup under each one, and then turned on the starter? A circuit error is just the electrics, I hope you didn't 'stretch' some wires where the loom enters the spark plug cover.

If you have a running engine, have a helper follow you around the block. Keep the gears in 1st or 2nd and the rpms around 3K and see if that helps clean out the combustion chambers. Have the helper check for smoke out of the exhaust.
--
Keeping it running is better than buying new

Had some spare injectors and swapped them. And pulled the injectors while running to see if engine idle changed. Didn't do cup test as had the CAT off at that point and didn't want fuel spraying around engine bay and detonating on turbo exhaust. There is absolutely no smoke. Didn't have my multimeter on me but will check all the cables next week. Dont think it's the cables on injectors though as the engine is running well now ( just under powered ) will update next week (car is 200km away from me). Thanks for your suggestions.

If there is only a little boost, check the intercooler connections. Just try twisting them by hand, if they move tighten the clamp. Also true at the air filter and throttle body.

Also check the 3 vacuum lines for the turbo. If they are loose - no boost. Also make sure those 3 lines are correctly positioned, a bad swap will negate boost.

The injector fault still bugs me...
--
Keeping it running is better than buying new