JeffreyDurbin

I am doing the timing belt and water pump replacement on a 1985S and I have been told to replace the radiator fan clutch at the same time as I do the water pump replacement. Does this make sense? It's $165 on RockAuto. For those who have done the timing belt and water pump job, what do you think?

Thank you.

JeffreyDurbin

Also, should I replace the Lower Idler Assembly? That's also a pretty pricey product.

Thank you.

Landseer

By lower idler assembly, do you mean that guide arrangement beneath the crank pulley ?

If so, replace the bearings and clips only.

Regarding fan, can't hurt, but check first with mark Anderson of 928 international, I heard rumor he has a replacement for less. It is possible to refill old one with thick silicon fluid. Usual symptom of fan issue is rising temps when idling at stoplight, but temp drops at hiway speed.

be careful where you get the pump...most important

hwyengr

I'll be a little more direct than Landseer, did you also get the water pump from Rock Auto? That is a recipe for disaster if you did.

Mark Anderson

thanks We do have one but its $195

SteveG

You should probably do some research. You may want to pay the $17.00 for membership here so you can search this forum. Otherwise you should call Greg Brown at Precision Motorworks or Mark Anderson at 928 International for advice on the water pump. Roger Tyson at 928sRus, is also a parts source and a trusted member here. They can give you options based on product reputation and price.

I'm not sure what you mean by "lower assembly" If it is the pinch roller at the crank, it was deleted at some point. If it is "iffy" with grit or stiff, Mark could advise whether it can be deleted on the '85 or should be replaced.

To positively ID parts there is Porsche PDF, E-928 Katalog. I think I got it here in another tech thread. That also probably requires membership.
Welcome.

DeWolf

Convert it to electric.

Randy V

Proactive parts replacement on a 928?

While you're at it, might as well replace everything!

JayPoorJay

There are a million things I don't know about these cars. I have an 86. All I know is I replaced the stock belt driven fan in my Jaguar XJS and I used SPAL fans. A 16 and 12 inch. I would say replace the Derale unit with a SPAL. Trusted, tried, true...

How I control my fans - whether it was a good choice YET to be seen - is with a "northern radiator" PWM control module. It gets good reviews, lots of folks with American muscle cars using them, amazingly small - a bit expensive... I don't know what to think OTHER than to say I HATE the way that the temp sensor mounts - a little sticky patch. There has to be a better way, and I'm on the lookout for it.

Anyone know about the northern radiator PWM controller (or a better one on the market), any innovations, any work arounds, any bad news or BETTER ways to get the temp signal for fan control ,,, I'm all ears.

bureau13

I'm currently in the midst of a timing belt job on my '86.5, and had to deal with these same issues.

Pinch rollers: I bought the replacement bearing (very cheap) from Roger, but it turns out that roller is spinning very smoothly so I don't need it yet. Leaving it alone. I wouldn't remove it, personally, it helps keep the belt in place as it goes under the crank.

Fan clutch: A while back, I bought the replacement fan clutch from Roger (I thought about trying the silicone oil replacement but it sounds like a pain with somewhat inconsistent results). It turned out my cooling issue at the time was far dumber and, while I am sure my old one could be improved upon, my cooling system works great even in South Florida summers, so I left it alone. However, now that I have everything apart anyway, I decided to do it. I'm actually regretting it a bit, because I've had a terrible time separating all the parts. I snapped off the end of the old clutch trying to get the nut off, so there's no turning back now. I did finally get the old clutch out of the rear bearing and out of the mount, but the front bearing has come with it. Both bearings are very smooth and I don't like to throw money at parts that are working fine, but I have not figured out a way to get that second bearing off the old clutch. It's up near the fan end, so there's no way to tap it off, and I don't have anything that can support it so that I can tap on the clutch shaft and get it out that way, and none of my pullers will fit well enough to be useful. So I will probably have to just buy another bearing (and I'm sure there's a decent argument for doing that regardless but still). Long story short, I will undoubtedly be glad that I did this job once it's done, but right now it's annoying me.

GregBBRD

No.
Replace it only if it is defective..
Better yet (although this takes some patience), fill it with fan clutch oil and re-use it.