406 8v Turbo - Warning light issues

Honest John Back Room » Technical matters
What is life like with your car? Let us know and win £500 in John Lewis vouchers | No thanks
View Threaded
Fri 20 Aug 2004 19:18
406 8v Turbo - Warning light issues - Rob-406Turbo
I have a 406 8v Turbo (1998) which regularly shows the engine warning light during hard acceleration and the turbo cuts out.

This is particularly annoying if your overtaking!!

I disconnected the battery for some time to reset the ECU - made no difference.

I have taken it to Peugeot for engine diag info. The results showed 2 errors recorded, one for the oxygen circuit and one for the turbo switch.

Peugeot have offered to change both for a generous £250!

However I can buy the parts for £130 - I think one is a lambda sensor and the other a turbo solenoid switch\valve.

Unfortunately, the Haynes manual does not cover the 8v Turbo (just my luck, I also have a VW Clipper which Haynes do not cover!).

Does anyone know where the turbo switch\solenoid is? I can't even find the turbo! I believe the lambda sensor is in the exhaust pipe just out of the engine.

I would like to check and clean the connections before buying the parts.

Many Thanks

Rob Francis
Reply | Report as offensive | Link
Fri 20 Aug 2004 19:28
406 8v Turbo - Warning light issues - LeePower
The Lambda sensor is screwed into the downpipe in front of the cat, best reached from under the car.

Ive no idea about the turbo im afraid.
Reply | Report as offensive | Link
Fri 20 Aug 2004 20:45
406 8v Turbo - Warning light issues - pugman
I drove a 406 Turbo for 55,000 miles, and it had the same fault. Often the car would give a burst of surprising acceleration, and then "flake out" with the engine management light on. It was clearly a turbo solenoid problem allowing the boost to get to too high a level. Never got it fixed though as it was intermittent.

Hence my advice is get the solenoid fixed first and see if the problem goes away before investing in the lambda sensor.

As an aside, I now own a 605 with the same engine. Had to put a new turbo on the car at 120k as the original became cracked (sounds like a blowing exhaust when engine cold - goes away when warm). Cost £900 to fix (Turbo from Turbo Technics + fitting from local Pug dealer). Apparently this is a very common problem with this engine, so watch out for that exhaust blow and sell quick if it does.
Reply | Report as offensive | Link
Mon 13 Sep 2004 19:50
406 8v Turbo - Warning light issues - Rob-406Turbo
I changed the Lambda sensor first (cheapest!) -£29+vat+delivery from www.cats-direct-shop.co.uk

Now the warning light comes on at higher revs - so little change is good? Mmmm - not sure!

Then I purchased the solinoid valve from Peugeot £39 + vat - so far so good. No engine management light as yet.

I now hope that is it solved.



Reply | Report as offensive | Link
Sun 21 Jan 2007 18:12
406 8v Turbo - Warning light issues - 406executive
where did you find the solenoid switch in the end please. my 8v 2.0 executive turbo died a month ago. now it will do no more than 20 in first, really strains, turbo not kicking in, thought cat had collapsed so replaced but no joy. anyone please help driving me round the bend, cant say i can hear any blowing from turbo. could it be diaghram in actuator gone ?
Reply | Report as offensive | Link
Sat 31 Mar 2007 15:59
406 8v Turbo - Warning light issues - 406executive
i found a second hand switch, fitted it - no difference, drove 80 miles - left car for 3 hrs then drove again and turbo great, working fine.
Reply | Report as offensive | Link

Looking for a garage you can trust? Honest John's Good Garage Guide has thousands of reader recommended garages, plus how-to guides and tips on servicing.

The Good Garage Guide