Looking for ideas here. My son says his 97 850 GLT is shaking pretty bad at startup. I havent experienced it myself, but he says it seems to do it more when it's colder outside. (Like now here in Ohio) I'm going to take a look at it with him tomorrow morning.

Something that may or may not be related: His CEL came on last weekend. I had him take it Autozone to get the code read. They didnt actually give him the code (of course), but told him it was related to the cooling system, i.e. thermostat, coolant not circulating properly.. something along those lines. I've had him keep an eye on the temp gauge and he says it stays normal. We are looking at that tomorrow too.

Any suggestions would be appreciated.

Thanks-

Jeff

 

Check the thermostat and ECT.

 

Thermo & other cooling system items:

http://www.fcpgroton.com/category-ex...136/by_year/47

ECT Sensor:
http://www.eeuroparts.com/Main/PartD...spx?id=9186486


JPN

 

Thanks for the ideas, Ill check into them. I think he might also have the OEM coolant cap, so Ill check that out too. Would this be related to the shaking when he starts the car? My thoughts were maybe a worn motor mount (unlikely since it doesnt seem to shake once its running) or perhaps the starter motor bolts are loose?

 

The OEM cap/starter bolts have nothing to do with the shaking. As far as I know, there are only 3 things that can shake the engine at start-up/idle:

- Worn out engine mounts.
- Rough idle.
- Earthquake.

When was the last time the car had a good tune-up? I would also like to know the mileage, as well as themixture ratioof the coolant (you can buy an antifreeze hydrometer for a few $ at an auto parts shop).


JPN

 

One thing to try is to replace the coolant temperature sensor. Our 95 Turbo had one going bad and it caused a lot of shaking at start up and the car would not idle properly until it really warmed up.

 

Thanks for the ideas. Didn,t get much done on Saturday since I had no parts handy at that time and it was dang cold. It will be even colder this weekend unfortunately. After reading your responses and talking to someone at work, it sounds like the coolant temp sensor is my best bet on the shaking, and is probably the reason the CEL is on to boot. I went ahead and ordered the sensor from Europarts (thanks for the link JPN!) along with front pads and rotors since he needs brakes too. I tried pulling the driver side front wheel on Saturday, but the lug nuts were torqued good from the local shop putting tires on for us. I,ll have to borrow an air tool or use and extension to get them off, I suppose.

Of course, it might be time to buy a compressor if I can convince my wife I REALLY need it...

I,ll let you know how it turns out.

Jeff

 

Hi Jeff,

We are glad to be of help. I looked for the ECT sensor at FCP Groton but could not find one. FCP Groton usually carries almost everything an 850 owner needs, but this time they did not seem to have one.

I once had the problem with one of the wheels. The left rear wheel was torqued with an impact tool, and I had to use a 1/2" drive breaker bar and had to hop-step-jump on it, not to mention the directional arrow on the sidewall of the tyres were in reverse orientation[8D]. Some shops do not seem to know that they are supposed to use a torque wrench on aluminium wheels.

Anyway, we will wait for your updates.


JPN

 

Update: received all the parts I ordered on Thursday and my son brought the car up to where I work at 3:30. The plant manager brought in an impact gun and we spun the lug bolts off fairly easily. The front brakes were a very simple job and everything came apart and went back together easily.

Removing the ECT was giving us trouble until I realized an alternator bolt was keeping the socket from lining up straight. (At first we thought it was the upper t-stat housing) After removing the offending bolt, it was a simple task to remove the old one and put in the new one. I don,t have a tool to reset the CEL and my son didn,t want to disconnect the battery and have to reprogram the radio, so we,ll just have to wait and see if this fixes the starting issue. Am I correct in assuming that if the sensor was the problem, the ECU will eventually shut off the CEL when it does a diagnostic and finds the sensor works again or must I get it reset/disconnect the battery?

We also tried to replace the antenna mast, but the non-working one was jammed in place and wouldn,t come out. We ran out of time so we,ll have to tackle that another day.

-Jeff

 

If the trouble code is "latched", it would have to be reset with an OBD-II scanner/Volvo tester. Simply disconnecting the battery cablemay/maynot extinguish it.

I hope the new ECT sensor would have fixed the shaking problem.


JPN

 

Fun, fun! The new ECT sensor did not fix the issue. Oddly enough, the shaking happens when its mildly cold and not when its dang cold. Had to wait until last Friday when it was mid 40-ish instead of in the teens or below before it acted up again. On Monday, we disconnected the battery to try to clear the CEL, whichworked. My son just called to let me know it didnt take long for it to come back on again. Guess we have to look at other options such as the t-stat, coolant mixture, etc. I told him to take it back to Autozone to get the codes read again since they didnt actually give him the code last time, just told him what things might be causing it.

On the up-side, I pulled the antenna assembly out of the trunk and managed to manhandle the old mast out of it and replace it with the new one, so at least his antenna works now!