P0128 Engine Coolant Temperture Sensor location? 2001 S60

norwood451 · Post by **norwood451** » 09 Jan 2009, 22:21

The received at DTC code P0128 indicating the Engine Coolant Temperature Sensor is not working properly. It is an inexpensive part, so I thought I would replace it. However, I can not figure out where it is. All the references I have read say it is in different places. What would be nice to see is a photo or illustration of the location. Anyway, if someone can describe where it is, that would be great. Thax in advance. 2001 non-turbo Volvo S60.

Post by **MadeInJapan** » 09 Jan 2009, 23:01

Welcome to MVS.
In the diagram below, you're looking at the timing belt side of the engine. If you replace the ECT (engine coolant temp.) sensor, you really need to replace the thermostat (#13) as well...they're both in the same housing and you're going to have to drain about 3/4 to a gallon of coolant anyway to do either.

: S60 ECT.jpg (42.9 KiB) Viewed 18099 times

norwood451 · Post by **norwood451** » 10 Jan 2009, 00:42

Thank you. Much better than anything else I have seen. However, I not sure exactly where it is on the engine. I guess I do not know where the Timing belt side of the engine is and the illustration you attached is too close-up. Do you by chance have another illustration that is farther back so I can see where the timing belt side is on the engine?

Post by **MadeInJapan** » 10 Jan 2009, 07:11

Maybe it's easier to say that it's on the passenger side (if you're in the U.S. and have a left hand drive vehicle, otherwise if you're in the U.K. and have a right hand drive vehicle, it would be on the other side). You'll find the housing for the thermostat (where the ECT resides) butted up and attached to the side of the engine block right under the larger radiator hose. I hope this helps (click to enlarge image):

: S60 ECT2.jpg (150.29 KiB) Viewed 18197 times

It is under where the hose attaches to the thermostat housing in the circled area in this picture:

: S60 ECT3.jpg (77.03 KiB) Viewed 18101 times

Btw, you'll have to take the hose off to reach the ECT. and it will aid in draining off coolant, which you will have to do in order to change the thermostat. A quick and dirty way to keep from draining from the petcock at the bottom of the radiator is to suck out the coolant in the overflow tank with a turkey baster, and then clamp both the small hose from the bottom of the overflow tank (it comes off easily from the sidewall) and larger radiator hose with a clamp. Still, I would put several large towels down under the thermostat housing area to keep coolant spilling into the belt areas to a minimum. Another thing to be careful of is that the two torx screws holding on the thermostat housing cover on some models are fairly soft and you can damage the heads quite easily. Make sure you have the right size torx socket and it fits flush and straight onto the bolt heads (I believe it's size T40 and you'll need an extension for the bolt closest to the fuel rail- some people find that a long torx socket is a better way to go). Many people soak the bolt heads with PB Blaster the the night before doing this job to aid in getting those out. If you do mess up one or both of these bolt heads, the dealer sells an upgraded bolt that is made of harder material, so you might want to go ahead and buy the newer thermostat housing bolts from them and have them on hand. About the thermostat- you'll have a choice of different thermostats (different temperature ratings). If you have a non-turbo, buy the one with less degrees...if a turbo, then one with higher degrees. VADIS instructions say to use a new housing gasket after cleaning the mating surfaces, but on older cars than yours there is no gasket, so you might want to see what's on your mating surfaces when you pull yours off (sort of thinking it won't have one). The thermostat itself has a rubber gasket around its edge that should come with it, and this in itself is enough to keep the coolant from seeping out the top of the housing. When installing the thermostat, make sure the little hole it it is pointing towards the front of the car and it is installed with the spring side down. Once you are finished with the replacements, put the overflow tank back in its original position and fill it up with coolant but leave the cap off, then start your engine, with heat on full blast...begin massaging the upper radiator hose. When your car warms up, it will open the thermostat (about 10 minutes) and allo coolant into your heater core- you will see bubbles come up into the overflow tank...keep massaging the upper hose and continue to top off with coolant until you see no more bubbles and the level is at the "full" mark. Now, put the cap on. You're done! In the next day, check your coolant level- it almost always goes down some. Never, open the cap back up with the engine hot- wait until it's cooled and add coolant again as needed. This repair is fairly straight forward and easy unless you mess up the bolt heads to an extent that you can't get the thermostat housing cover off- just be careful and take your time. If you're not in a hurry to do this job and you haven't bought your parts yet, both http://www.fcpgroton.com and http://www.eeuroparts.com sell all of what you need (including the bolts) at a considerable discount over the dealer. I Hope the information I provided helps.
Good luck and let us know how you do.

norwood451 · Post by **norwood451** » 10 Jan 2009, 14:17

All I can say at this point is WOW!. Thanx so much, I will let you know how it goes.

Post by **MadeInJapan** » 10 Jan 2009, 14:32

Good luck and let us know how it goes...to be honest, if you've done one once on pretty much any Volvo AWD/FWD, it's fairly easy and can be done in less than 30 minutes.

norwood451 · Post by **norwood451** » 10 Jan 2009, 14:53

Just one more question before I order the parts. You mentioned the need to replace the thermostat. I'm sure it is best and you must be right, but it looks much easier not to change it & less expensive. Would you mind letting me know the reason why the thermostat should be changed with the coolant sensor?

Post by **MadeInJapan** » 10 Jan 2009, 15:53

They all go eventually anyway...it's a $15 part (or less) and sometimes the ECT can act up if the thermostat goes- Besides, you're having to drain coolant anyway- just best to replace in pairs.

Post by **JRL** » 10 Jan 2009, 16:16

norwood451 wrote:Thank you. Much better than anything else I have seen. However, I not sure exactly where it is on the engine. I guess I do not know where the Timing belt side of the engine is and the illustration you attached is too close-up. Do you by chance have another illustration that is farther back so I can see where the timing belt side is on the engine?

Right side (looking left if you're in front of the car)

bshinn · Post by **bshinn** » 21 Jan 2009, 16:22

NE1 konw the torque specs for the T-stat cover bolts?