I have 144K km on my 1989 740T. Most of my mileage is low speed city driving. When should I replace the timing belt. I have periodically had it checked and been told that it is in good shape. According to the records of the previous owner, it was first replaced at 75K km in arounf 1997.

Other than routine maintenance and fluid changes (also replacement of front shocks, power steering components and rack, voltage regulator), I have done very little to vehicle and it runs well(except occasional rough idle). Is there anything else I should be doing; tune up etc.? If i have timing belt replaced, is there anything that I should be doing at same time?

Agree with other posts / would also be sure to
> Timing belt / seals / tensioner / water pump / t-stat / coolant hoses + tank
> heater hoses and heater control valve (use Volvo on these)
> rear axle pinion seal (input seal from driveshaft)I use dealer to do this
> RPM sensor, Fuel pump relay, Radio suppression relay,
> seals at rear of head where distributor drives
I use synthetic oils / synthetic gear oil in rear diff / and flushes as
previously noted.

This website pretty much has all this if you go through it / FAQ
the items Mentioned are critical and most certainly will fail if neglected

If serviced car should run several hundred thousand miles

Steve,

The T belt should be replaced every 80K km (about 50K miles)so you are getting close. I'd also replace the alt-waterpump, ps, ac drive belts when I do the T-belt. They are usually good for five years and you have to remove them any way for the T-belt change. I always install a new water pump, T-stat, flush the cooling system and replace with fresh coolant. If the rad, or hoses look bad , it's a good time to replace them as well. The front oil seals can be renewed if they are leaking ... the T-belt tensioner bearing can also be replaced at this time if needed. Usually there are good for 150K miles so the next T-belt change may be the best for the tensioner and seals.

As far as a tune up ... NGK BPR7es plugs, Bosch distributor rotor and cap, possibly new plug wires, new air filter, new fuel filter(should be replaced every 60K miles). Clean the throttle body. You may consider replacing the auto transmission fluid, check the 700/900 FAQ for the proper procedure. I use Mobile 1 snythetic ATF. You can use M1ATF in your powering steering as well. Good to flush that every two years or so and replace the P/S fluid. Same with the brake fluid ... it should be replaced every two years. If your running a manual transmission drain and replace the type F with a high performance synthetic like Redline MTL. I've replaced the dif oil in all my Bricks with Mobile 1 synthetic gear oil.

The list of things you can do goes on and on ... but these are a few of the basics. Hope your brick stays well and happy ... and rollin' down the road for many more miles (in your case Kilometers). Good Luck.

Steve,

I believe the replacement interval is 80k km. I just had mine done at 162km on my 91. If yours was done in 97, it is not terribly old, so I would go till 160k. I understand that visually it is very hard to determine the condition of a timing belt.
I had all the front seals replaced at the same time. My camshaft seal was leaking. It is less expensive than going in later just to replace seals. Some might consider the water pump too, as they do on many front wheel drive imports when doing the timing belt. Routine maintenance like plugs, wires, rotor and cap, and air filter may not be a bad idea, and check all your turbo and vacuum hoses too. I have read that rads on these cars start to go at this age also, so this is the next thing on my list. If your car is a manual, consider having the trans fluid changed also, and go for some synthetic.

The rough idle is probably dirty throttle body, a spring time job for me.


Sean
--
91 740T M46

While I'm sure there are some situations that would be hard to predict.. there are a few telltale signs to look out for:

If the timing belt is oil stained (fix the leak, then replace the belt)
If the timing belt is cracked or belts are showing (replace the belt)
If the timing belt is extremely loose (rotate crank 1/8 turn, re-check, if loose re-tension, and re-check, if still loose, replace belt).

Under any of the above conditions, you've got a greatly increased risk of the timing belt slipping and/or breaking. On a B230, the t-belt is a bit easier to check since you only have to remove the top part of the cover.

- alex

'85 244 Turbo
'84 245 Turbo