1998 S70 GLT Fluctuating Temperature Gauge and hot starting?

[ashyu]

When driving, I've noticed that my car's temperature gauge doesn't always stay at 3 o'clock anymore - often times it will dip down noticeably. It does this gradually (so I won't usually see it by staring at it).

On the way back home from work today, I decided to pay a bit closer attention to it, and I even plugged in an OBD reader and monitored the coolant temperature reading while driving.

When in start/stop traffic, the engine eventually warmed up to around 88-90 C, which put it right at the 3 o'clock mark. However once the traffic cleared up and I was driving at a continuous speed (anywhere between 50 kmh to 100 kmh), the temperature started dropping, and the needle dropped noticeably below the 3 o'clock mark again. The coolest I saw it get to was around 74 C, although usually it seemed to average around 77-78 C.

It is the start of winter now, and the temperature outside was around -10 C, but I didn't think that the engine/coolant temperature should fluctuate that much while driving?

The other thing that I've noticed lately about my car is that while it starts up fine while cold, sometimes after doing a bit of driving, parking and shutting the car off, and then soon after trying to start the car back up again (say going to the store, or gas station, etc), more and more frequently the car will have trouble starting up. I usually hear a whirring or screeching sound, but the engine doesn't catch. Sometimes it'll eventually sputter to life, but other times it takes one or two more tries before it starts.

I did try searching online about the starting issue, and people noted quite a number of possibilities anything from the fuel pressure regulator, fuel pump relay, and even to the fuel pump itself, and various other sensors in the vehicle (although, with respect to 850's).

I did see one person even comment about the thermostat/temperature sensor, noting that if the ECU was getting an incorrect temperature reading at start-up, it could affect the fuel mixture?

Is there anyway I could verify if my thermostat/temperature sensor are working properly?

When I got home, I did try this:
1) Noted that the coolant temperature was only 78 C (needle below 3 o'clock mark)
2) Shut off engine for a brief while
3) Tried to start engine again - it didn't start, but I could hear the high-pitched screeching (is this the starter?)
4) Eventually got the engine started again on the second try
5) Let the engine warm up to around 87 C (needle at the 3 o'clock mark again)
6) Shut off the engine for a brief while
7) Tried to start the engine again, and it started without any incident!

Of course my test was completely unscientific...

I was considering looking into how to replace the thermostat and temperature sensor, but could there be bigger problems I might be facing? Or could I be looking in the wrong place?

[scot850]

Thermostat, and starter motor bendix is failing.

Neil.

[erikv11]

What Neil said: the two problems are likely separate.

(1) It needs a new thermostat. A lot of people elect to replace the ECT at the same time, it is up to you. Go with OEM on the ECT, part number and sources have been posted several times recently. Wahler on the stat. Gates sells Wahler stats in their Gates boxes.

(2) The starter is going out. I would probably go with a junkyard unit, or you can get a rebuilt one.

[ashyu]

Thank you both for the confirmation. I appreciate it.

Neil, I notice you're in Calgary - do you have any suggestions for a good place to get Volvo parts in Alberta (I am in Edmonton..)? I have ordered from IPD before, but the shipping is a bit more to Canada.

[scot850]

Hi ashyu. I don't buy much in Alberta as the parts are too expensive. When I have time and several parts to buy, I buy from Tasca Volvo in US. OE parts are about 40% cheaper. Insist on USPS and NOT UPS for shipping. For a starter motor, there are probably specialist repairers in Edmonton, so buy a re-manufactured Bosch unit. Do you not have a pick n'pull in Edmonton? We have 2 here with several Volvos (850's and V70's). 850's should also have the same starter motor after 1995. Earlier than that they are a longer starter motor, and you need to buy a shorter mounting bracket (or if used take the one it is using).

If you PM me your e-mail address, I'll send you info on who/where I buy stuff from.

Have you tried Sandy Lane in Edmonton? I know they can be expensive, and don't know if they have used parts. There is another Volvo repair shop up there in Edmonton, but can't remember the name.
There is also Revolv in Saskatoon. Chapman Motors out on Vancouver Island they can be pricey, but they have never sent me a duff part.

Neil.

[ashyu]

I did find a Pick-n-Pull in Edmonton, but it looks like they only have a couple 960's (1992 and 1996) and one 240. Will a starter from a 960 fit?

Thanks for the tips, I'll check out some of those places.

I have used Sandy Lane a lot for servicing since moving to Edmonton a couple years ago, but as my S70 ages (over 350,000 km now), I'm starting to look at what repairs/servicing I can do myself to save money - so I'm still pretty new to all of this.

[scot850]

There is a slim chance a 960 may fit an 850 according to FCP Euro website, but it is unlikely. A 98 S70 is similar to an 850 with a different body. 99 on are different engine wise.

I'd look for a re-manufactured unit. Try your local alternator/starter repair shops to see what they can offer. I know it will be more money, but go for a Bosch re-manufactured unit. I have not had luck with other brands, including not even fitting the car, or electrical fitments that were in wrong places, or just poor life-span ( 3 months!!).

The problem with buying on line, is most places want a deposit for you to return your starter. Often this is less than shipping back. Try Chapman Motors on Vancouver Island. Tell Happy Neil from Calgary suggested you call them. I have never had a problem with any part except for the price.

Good Luck!

Neil.

[ashyu]

Just reporting back, I found a couple places in Edmonton that do nothing but alternators and starters, Smith Electric and Alter-Start (Volvo of Edmonton pointed me to the second one).

I ended up picking up a remanufactured starter from Dixie Electric through Smith Electric for $145 + $25 core deposit. Alter-Start offered to rebuild my starter for me for something around $160. However, I still needed the car, so I couldn't wait a day for them to rebuild my starter (and at a higher cost than the off-the-shelf reman from Dixie Electric).

Spent the day swapping out the starter, and after getting everything back together, the car seems happy. Time will tell as the weather gets colder if the starting problems have been eliminated. I don't know if it's psychological or not, but the new starter sounds quieter and seems to start up much faster than the old one. It was my first time digging that deep into the car, but I somehow survived!

I ended up ordering a thermostat online for around $20ish shipped from a store in the US. Once that arrives, I'll put that in too.

Thanks again, Neil and erikv.

[luckykolo]

Did the new thermostat fix the issue? My Volvo displays the same symptoms. While driving 165F (74c). While in traffic or idling: around 210F (99c). It's about 50F (10c) degree difference. I have already replaced thermostat and sensor once (about 3 years ago). Back then the car was running really cold due to the thermostat being stuck. All parts OEM. Interestingly symptoms showed up after timing belt job. Water pump was replaced too btw. Unfortunately I had to outsource the job to the local shop, but I don't see them messing around with the thermostat housing??? At first I thought that the car needs to "burp" but 3 months later nothing changed. Coolant's level is ok. I have even replaced the coolant.

[abscate]

Thermostats first Volvos in this Forum regulate to either 87 or 90c, the “ set point”

Your coolant temp should never go under the set point, it will go over by 5-20C in warm weather in stopped traffic, the fan will turn on, and the coolant temp will return to the set point.