Hi all, I'm brand new here.
I am getting a code P0026 on our 04/05 V50. Looking around online it seems I could do with a new part that I don't understand. I've read about cam reset valves and intake reset solenoids. Which I assume are the same thing. But I don't understand exactly what it is I'm looking for or what it looks like.
Can anyone point me in the right direction online so that I know what I'm actually looking for?
Thanks!
That code relates to the variable valve timing solenoid for the intake.
If you have a 2.4 petrol, it is located near the oil filter cap and looks like this:
I had a different code and replaced this part with one I bought from Amazon for 105$ but it didn't solve my problem. There are some electrical/mechanical tests you can do on VIDA if you want to test before you try replacing.
Thanks so much Johna. Really appreciate the effort you went to with the photos.
What is VIDA? Complete noob here, I can replace bulbs and top up oil and coolant but still learning much more than this!
Those photos are from when I last tried to fix my fault.
VIDA is Volvo's service information and diagnostics software.
I had a look and these are what Volvo say can cause VVT error codes:
-Short-circuit to supply voltage in the signal cable.
-Open circuit on cable harness to VVT-unit.
-Poor engine oil quality
-VVT-unit tightened with too high torque against camshaft.
-Damaged camshaft reset valve
-Mechanical fault in the continuous variable valve timing (CVVT) unit.
-Incorrectly adjusted camshafts.
-The timing gear belt has jumped off the cogs.
Somewhere in VIDA there is some electrical tests you can do but I can't find it now. I think it just involved applying power and checking that the valve moves. There are also some instructions somewhere on how to clean the valve.
Assuming you have a 2.4 petrol non-turbo then the part number for the valve is 36002687. There are cheap Chinese valves for A$30 on aliexpress.com (presumably bad quality) up to several hundred dollars for a genuine one. fcpeuro.com have genuine ones for US$120 and a cheaper aftermarket option and are quick to deliver from the US.
Thanks heaps mate. That's all a ton of excellent info for me to digest. It sounds like it could be a range of different things and it's not a simple job to figure out what.
Hi Jono.
The variable valve timing uses a hydraulically adjustable cam sprocket. The cam timing (ie the advance or delay from the base timing) is adjusted by pumping engine oil into this "VVT unit", and this is done by the engine computer rapidly cycling the solenoid off and on so that engine oil from the oil pump is added or drained from the VVT unit constantly. The timing codes (P0026 etc) mean that the engine is wanting XX degrees adjustment and is cycling the solenoid to try and adjust the hydraulic flow, but is not measuring the timing it wants on the cam position sensor.
That's why the root issue could be the base oil pressure, the solenoid being faulty (or having a clogged filter screen), the solenoid wiring or fuse being faulty, the cam phaser (VVT unit) being faulty or blocked, or the cam position sensor being faulty (the trigger being loose or the sensor air gap being too large, for example.)
Long oil change intervals suggested by the factory don't help. If the oil used by previous garages is the cheapest junk they can buy in bulk, and changed at 15,000km plus or minus 5000km depending on the owner, then the sludge accumulated in the oil will clog the screen, solenoid or phaser. The cheapest starting point is possibly changing the engine oil to a good quality (slightly thicker) grade including a good engine oil flush product, and see if the desludge process helps. Then, it's a matter of going from easiest to access (eg solenoid, cam sensor) to hardest to deal with (timing belt, cam phaser). Having an oscilloscope to see the output from the cam sensor would be helpful, but even most garages don't have this…
Many thanks nh! That's good advice which I'll be considering. Thanks for sharing your wealth of knowledge.
