Timing belt tensioning

[Porsche-O-Phile]

OK, a question for all you old 944 guys (without the auto-tensioning timing belt):

How often do you REALLY tension them (I know every 15K is recommended, especially given the consequences of a broken one - it makes me shudder to even think of it), and how do you have it done? Do you take it in or buy the parts and the VERY expensive tools and do 'em yourself?

Just curious, I'm probably going to want to do this for peace of mind in the next 3-6 months or so (it's been about 12K since the last time - previous owner had a mechanic do it) and I need to know what's involved in terms of cost for a mechanic / dealer to do it or for me to do it. I don't mind doing the work, but the tools are AWFULLY expensive (though less so than new heads / pistons I suppose)!

Thanks!

[Zlatko]

Mine is a 200 Kilometers...and i can hear a whining coming from the engine bay...

I think im gonna go and get a mechanic to look at it..ive been able to fix most of the smaller stuff..but i dont have the tools necessary for a tensioning.

[Lawrence Coppari]

My 944 is a track car. I replace the belts every year. Just did them last weekend. I use a tool other than the expensive one but could probably get by just fine now by feel. Others on this list do it by feel. Others would only use the expensive tool.

As for which tool is best, you may as well ask which religion is best. Opinions vary widely on this one.

[SoCal Driver]

If you replace the belt at 25k to 30k and check the tension at 5k most have no problems with using the less expensive tension tool.

It is very important to change any toothed tension pulley at the slightest sign of bearing failure.

It is better to have a slightly loose belt than a belt that is too tight. The engine expands enough at temp to eventually cause a premature belt failure.

[joes]

It is important that all the tensioners and idlers and water pump (turbo conversion)be in good shape. They are often over looked and probably cause more noise and belt failures as much as a little tight or loose belt. After you get used to checking your belt you can get a feel for how tight or loose it is but my experience has been that the whole belt system has to have been neglected before it fails.

[Zlatko]

Hey guys...

I got in contact with a porsche 944 mechanic..

He told me that they charge 85/Hr. Now, i need to know how much a belt tensioning would take..

[Porsche-O-Phile]

Thanks guys,

According to the tensioning procedure in Haynes, it doesn't look like it'd take more than an hour or two to do on these things, provided you have the right tools.

Does anyone know of a conversion to go to a chain (or better yet, gear) drive for these things? The little bit of extra noise might be well worth the added piece of mind that I'm not going to trash my valvetrain / piston / block on a bad day.

[Lawrence Coppari]

The belts are rather durable. Many cars use them. Do it right and you don't have to worry.

Gears wouldl cost too much. Chains streach and break too. I have several Mercedes automobiles. They all need a chain at about 100K. They also need the sliders replaced which is a real ***** to do.

Personally, I'd rather deal with a belt.

[Taz's Master]

Not 100% certain, but I would believe (especially since the timing chain cover on a SBC has a gasket) that a chain or gear drive would need lubrication. Our Porsches are designed so that the belt area should stay dry. I don't see how a chain/gear conversion would work. Probably the easiest way would be to swap to an engine designed with a chain.

[Lawrence Coppari]

The chains on my MB cars are lubricated. Plus one of mine has an oil pressure chain tensioner that complements the spring load on the tensioner. They (the housings) are not prone to leaking, however. The chains are double width - like two running parallel except they are attached to one another with a double sprocket configuration everywhere.

In 1981 MB tried to use a single link chain- 380 engine. They replaced a number of engines due to chain breakage and returned to the double link variety. Don't know about the new ones, however. I've never seen what variety chain is on my 2002.

[TNT25169]

Taz's Master,

How hard was it to put turbo brakes on your car? Did it make a big difference and was their any custom fabricating?

[Taz's Master]

The PO's were generally unkind to my car, however they did upgrade the brakes, for which I'm grateful. Can't comment on any improvement, because I never drove the car any other way. I believe you need the calipers, rotors and spindles from a turbo car. Since the swap seems to have worked well, and there is evidence of previous (and current) mechanical ineptitude I would have to say that the swap was straight forward (they may have swapped the entire control arms). You also need the 16" wheels. If you get the hardware from an '86 be aware that you have only 1 year of turbo production wheels and they can be difficult to replace (or simply acquire).

[AFJuvat]

Originally posted by Zlatko
Hey guys...

I got in contact with a porsche 944 mechanic..

He told me that they charge 85/Hr. Now, i need to know how much a belt tensioning would take..

Tensioning takes approximately 1 - 1.5 billable hours.

AFJuvat

[Porsche-O-Phile]

Thanks again,

I think for peace of mind, I'll take it in to a local German car specialist I know this week & have him tension or replace the belts. I hate to pay $200 on labor that I know I could do myself, but I just don't feel right doing it "by feel" - too much at stake. I'll save up & get that little tool though and sleep with it under my pillow for the warm soft fuzzy feeling it'll give me

[GHEN]

It really only needs to be domne every 30K miles, or 2.5 years whichever comes 1st.