Another timing belt question...

stick1975 · 02-09-2009, 07:07 AM

Reading the last thread made me wounder, my car has had a new belt, water pump, hoses, and rad. since about 2001. The has had maybe 50 miles put on it, then it just sat with electrical issues up until a few months ago when I decided to start fooling with it again. My question is with the tension on the belt over that long period of time warrant replacement? The car has about 98,000 miles on it. What do the experts think?

MPDano · MPDano's Garage

Thats a long TIME ago. I think TB's recommended changeout is around 5 years or so. Your way over that. That rubber belt is aged like fine wine. I would replace it, why chance it.

Danglerb · 02-09-2009, 10:56 AM

Frankly I would worry more about the coolant after sitting 8 years than the timing belt, but I still would not start it without checking the tension etc. first.

How much confidence can you put in the work done by the previous owner? I mean it goes in for a routine service of the TB and WP and 50 miles later it doesn't run and gets parked.

Maybe its beating on a dead horse, but I would start with a thorough inspection, like a PPI, except its too late to run away.

**** On the specific point of the belt, if the tension and cam timing are correct, and it tracks well, then I think you need to drive it a bit, a dozen full heat cycles, 1000 miles, whatever and then check it over again to see whats leaking etc. before diving in, unless you want to redo the whole TB and WP job.

Rixter · 02-09-2009, 10:58 AM

depends on the MY... 78-79 CIS I'd get it running without worrying about the belt, it's a non-interference engine (theoretically)... any 32v and I'd be doing the tb/wp before even attempting to start it

N2O-SHARK · 02-09-2009, 02:44 PM

^Agreed. Get it running first, then change the belt. No sense changing the TB if there are more catastrophic issues to be delt with.

artikulieren · 02-09-2009, 08:34 PM

Speaking of timing belts... I just came in from the garage with a timing belt woe (or shall I say WHOA!) of my own. I will not be starting my 87 again without a TB service. I have just pulled the cover to give it a look and the edges are simply a mass of tiny cracks... I think it is miraculous that it hasn't already snapped and I shiver knowing that I ran it recently... Anyone have a ballpark on an acceptable number of chargeable hours a TB/WP service should run me at the neighborhood P-car shop? as to make sure I don't get fleeced when I go in for an estimate...

rhjames · rhjames's Garage

depends upon model year as said here.

5 year--50,000 mile changeout recommended regardless of condition.

16V non-interference? fire it up and run it until it breaks (not if, but when)

16V interference or 32V, don't even think about start up. it could immediately break and bend valves. Got a few thou to do that experiment?

if you are CIS, over 1 year of no run will be a nightmare for you and the fuel system.

otherwise, it's fuel pump/tank cleaning/hose replacement/this list can get big......

Art--

get the parts (kit) and find a local 928 group where you and the bunch can make a day of it (TB/H2o party). It's more fun that way, and you'll save a bundle.

--Russ

Danglerb · 02-09-2009, 09:09 PM

I think 10 shop hours is common, if a shop is foolish enough to quote a flat rate. Its one of the jobs that can easily grow once you get into it. Its also a job I think some inexperienced shops screw up. After 1000 miles the belt tension needs to checked and adjusted if its off, find out if thats included in the quote.

stick1975 · 02-13-2009, 06:24 AM

This is the 84 car I have had the injector signal problems with. I did the work on the car back in 2001, then it sat at that shop waiting for the PO to pick it up. The only service records I could find on the car was PDI when it was new. So who knows what have been done. I horse traded for the car, and have had it tucked away untill the last few months. When I pulled it out of storage, I replace the fuel pump and filter, pulled the plugs and oiled the cyl. and installed my rebuilt $350 ECU. Now I have the elc. center out to clean all the contacts. I was just looking on here and seen a timing belt question that made me wonder. I guess the belt sitting with tenison on it is different then one sitting on the shelf.

Danglerb · 02-13-2009, 09:12 AM

US 84 is non interference, get it started and check it out, then start looking for places to spend time and money. I'd check the tension and make a good visual check first.

What are your plans for the car? Years of weekend fun, or selling it?

stick1975 · 02-14-2009, 04:54 AM

Well my sickness started with this 84s, so I hope to make it drivable and play with it for awhile. Its still in fare shape, no show car but an unmolested survivor. With a little lipstick and rouge, it would be a good weekend car. I also have an 82s that I bought for parts with the broken timing belt that I want to put the LS1 in.

Danglerb · 02-14-2009, 02:09 PM

I got my first up close and all the time I wanted to spend look at a Renegade kit Chevy swap yesterday. If the owner doesn't mind I may post a thread later on.

The LS1 has more cheap power potential than the factory 928 motor, but the net result is a more complex vehicle. I am edging toward a CIS car being the best choice for a swap, much simpler electrics and much less interaction with engine control.

stick1975 · 02-16-2009, 12:13 PM

The 82 car will be more of a hulled out street fighter, so I hope that I can make it a whole lot less complex, less engine management of course. I have looked at the renegade sites, but have yet too see a car in person. I like the idea of the best bang for the buck combo.

Danglerb · 02-16-2009, 02:42 PM

The 82 ignition and fuel computers are tied in to the rest of the cars electrical system and instruments. The 928 wants all the special signals its used to getting from the brains, and the Chevy motor and its brains want all the signals its used to getting from a Chevy.

Many people try an older carb and points motor, but expect to be reminded why every modern car doesn't use them anymore.

stick1975 · 02-17-2009, 07:39 AM

I hope that I can use Porsche sending units in the Chevy motor to make my stock gauges work. I don't mind tearing into the wiring harness to "clean it up". The people that will burn the program for the LS1 motor can turn things "off", like EGR, secondary O2 sensors, air pump and so on. So at least with the Chevy computer I don't think it will that big a deal, with the Porsche harness, I must admit I don't know. What outputs will the car be looking for other than signals for the gauges?

Danglerb · 02-17-2009, 08:06 AM

Quote:

Originally Posted by stick1975

I hope that I can use Porsche sending units in the Chevy motor to make my stock gauges work. I don't mind tearing into the wiring harness to "clean it up". The people that will burn the program for the LS1 motor can turn things "off", like EGR, secondary O2 sensors, air pump and so on. So at least with the Chevy computer I don't think it will that big a deal, with the Porsche harness, I must admit I don't know. What outputs will the car be looking for other than signals for the gauges?

You don't want me to spoil the adventure for you do you?

Here are a couple good links to get you started.

http://www.porschehybrids.com/php/

http://www.ls1tech.com/forums/conversions-hybrids-28/

stick1975 · 02-19-2009, 11:15 AM

Joined those two sites today. Thanks for the info.

surfdog4 · 03-11-2009, 09:20 AM

I waited to do the timing belt after i had other things (like the vacuum lines, etc) done. One HUGE mistake i made though was to tighten the timing belt without having the Kempf tool ('cause it seemed loose to me). The result was i over-tightened it, then it pulled down on the idler pully, end result was the timing belt was slowly being chewed up...so then I HAD to replace the timing belt

Lesson learned: don't tighten the timing belt without one of the proper tensioning tools..

Danglerb · 03-11-2009, 11:15 AM

Damage from over tensioning the belt I think is MUCH more common than many will admit.

2Quick4u928 · 03-11-2009, 11:24 AM

I regards to this potential TB service...Have a question regarding the 10mm bolt after new tensioner roller installation (Step 13 TB Svs. Rennlist)...I cannot locate a torque spec for this bolt. Directions here state "Turn tensioner screwbolt counter-clockwise to full loose." Just does not make sense to me as the nut could vibrate off then later roller decides to bounce around like a pin-ball machine inside the TB covers. Inputs? About to check the svs manual right now....thanks