Hello Folks,

I wanted to see if anybody reading this might be able to make sense of my current collection of ODB codes... My car is a 2000 V40...

Currently it has been rough-idling at startup... now today while driving a longer distance than usual, I noticed a new symptom crop up... the interior heating blow of air would not get warm... always cool, even after driving for a while. Then I noticed my temp gauge creeping up to near red a number of times... rather alarming as it almost always has been "dead-center" horizontal almost always.

So... here are the ODb codes I am getting:

P0128
P0014
P0015
P0303

I suspect that I either having a timing gear issue, or the "camshaft position sensor" is faulty, as far as the bottom three codes, and I suspect my thermostat died in the closed position?

Any thoughts out there?

Thanks.

Thanks All...,

I did a little research and it seems that changing the thermostat on my model will be pretty easy. It's located at top of engine and visible. From all I've read elsewhere also so far, the thermostat def seems to be the smartest part to replace to start with. Hopefully it may even clear up the other issues?

Since the tube leading to the thermostat housing is relatively level with the top of the radiator, I'm wondering if I could get by with not draining the coolant?... Could I manage to just unloosen that tube, have a catch-bag or plastic under it, and let just that fluid trickle out? Seems like it wouldn't be much?

You do not have to drain the entire cooling system to replace the thermostat.
However, if it's been years since a "flush", it may be a good idea as suggested by others.

I replaced the thermostat on my 2001 S40 a few years ago and did not drain anything. There may have been some minor spillage, but I don't recall anything major.

Of course, you should make sure the cooling system is filled to capacity after you complete the repair.

Suppose you could try that but you are still going to need to bleed/burp the air out of the system after installation. It was a long time ago, but as I recall that is what I did on my old 240.

OTOH - If you haven't changed your coolant for awhile now would be a good time...:)

Definitely use a factory or OEM thermostat.

Check your coolant level twice, cold engine and warm. If it gets too low, you will not get any cabin heat. I agree with the others regarding a failed thermostat. The cheap after market versions typically fail in a closed position, causing immediate overheating condition.

After changing the thermostat, clear the codes and attack any that come back.
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Keeping it running is better than buying new

I agree. Switch the thermostat before doing anything else. Sure sounds like it could be that the thermostat is stuck closed.
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Will I buy another Volvo??? We'll see....

I hate recommending the "parts cannon", but it may be worth your while to replace the thermostat before trying to chase a camshaft position sensor or the timing issues. My suspicion is that the ECU is compensating for a failing or failed thermostat. No guarantees though!

A thermostat is relatively cheap (< $20). However, I avoid ebay, discount auto parts stores etc. as it is unlikely that they would offer an OEM (original equipment manufacturer) product which is important for this item in my opinion.

These guys are very supportive of the old Volvo hobby and offer factory and OEM parts. I am not affiliated with them other than being a customer.
https://www.fcpeuro.com/Volvo-parts/S40/Engine-Thermostat/?year=2000&m=20&e=2007