Timing Belt Warning Light
12-19-2005, 12:30 PM
#1
Racer
Thread Starter
Join Date: Oct 2005
Location: middle of nowhere, USA
Posts: 309
Likes: 0
Received 0 Likes
on
0 Posts
Timing Belt Warning Light
How exactly does the timing belt warning light work? Is it tied to the tensioner or is it a stand alone item? What years had it and did it change in later years? Can it (or something similar) be adapted to earlier cars and is it even worth the effort?
12-19-2005, 03:14 PM
#2
Three Wheelin'
Having 4 sharks and not knowing all of the ins and outs of the timing belt system is like having 4 ex wives and not knowing what a prenup is for!
J/K
The warning system is tied to the tensioner. I wouldn't retrofit the system to the earlier 16v cars as they are reputed to not be interference engines and thus would not suffer the catastrophic valve train damage the later 23v would.
J/K
The warning system is tied to the tensioner. I wouldn't retrofit the system to the earlier 16v cars as they are reputed to not be interference engines and thus would not suffer the catastrophic valve train damage the later 23v would.
12-19-2005, 03:54 PM
#3
Under the Lift
Lifetime Rennlist
Member
Lifetime Rennlist
Member
Erich:
85 on has the warning system. Retrofit is out of the question, and not as essential, as Dave noted. Lots of parts are different.
85 on has the warning system. Retrofit is out of the question, and not as essential, as Dave noted. Lots of parts are different.
12-19-2005, 04:59 PM
#4
Rennlist Member
Originally Posted by Bill Ball
Erich:
85 on has the warning system. Retrofit is out of the question, and not as essential, as Dave noted. Lots of parts are different.
85 on has the warning system. Retrofit is out of the question, and not as essential, as Dave noted. Lots of parts are different.
My '80 has the full HTD belt upgrade, back cover, crank idler, etc ... with the '85 tensioner .... and the ground loop belt tension alarm wiring grafted out the center cam cover. Without the 3 min delay function, the alarm system can be emulated with a single 5-pin SPDT relay ( as in the power window circuit), a fused 12v switched power feed and an alarm source ( red led in my case). If I was really ambitious ( read '****'), a 3 min delay circuit could be added - but that would be over engineering ...
12-19-2005, 05:48 PM
#5
Racer
Thread Starter
Join Date: Oct 2005
Location: middle of nowhere, USA
Posts: 309
Likes: 0
Received 0 Likes
on
0 Posts
Given that I am in the midst of healthy engine modifications it is quite possible even my 16v sharks will be interference by the time I am done, I hope to find a way to prevent this but compromise all too often dictates such things. Exactly how does the light warn? Strictly on a lose belt situation? I assume the circuit is broken by the loss of pressure on the tensioner? Is the system truly a warning or just another "idiot" light that tells you after the worst has happened?
12-19-2005, 06:01 PM
#6
Under the Lift
Lifetime Rennlist
Member
Lifetime Rennlist
Member
Garth, I knew you would find a way to show this can be done. So, go through the parts swap. Tensioner, tensioner arm, at least right? What else. Sure, the electrics, baring the 3 minute delay, are dirt simple.
12-19-2005, 06:11 PM
#7
Under the Lift
Lifetime Rennlist
Member
Lifetime Rennlist
Member
Erich:
Tony Harkin has it all explained here:
http://members.rennlist.com/v1uhoh/timing.htm
It's pretty sensitive to tension, so it does warn before the catastrophic event, but not always depending on the failure mode. It is an idiot light. It can false alarm in the sense that anything that breaks the circuit, such as a loose wire, will trip it.
Tony Harkin has it all explained here:
http://members.rennlist.com/v1uhoh/timing.htm
It's pretty sensitive to tension, so it does warn before the catastrophic event, but not always depending on the failure mode. It is an idiot light. It can false alarm in the sense that anything that breaks the circuit, such as a loose wire, will trip it.
Trending Topics
12-19-2005, 09:17 PM
#8
Rennlist Member
Originally Posted by Bill Ball
Garth, I knew you would find a way to show this can be done. So, go through the parts swap. Tensioner, tensioner arm, at least right? What else. Sure, the electrics, baring the 3 minute delay, are dirt simple.
The first step is to fit the HTD TB and four matching drive gears from an '83 - '95; '85 and up 32v cam drive gears do work, but their wider woodruff slots for 32v cam timing are an unnecessary complication on most 16v's. Stick with the '83 - '84 cam gears. This TB update is independent of tensioner choice.
The '83 - '85 tensioner is the one with two bleeder bolts vs bleeder screws as found on the '86.5 on. Use the '85 version as it has the ground loop mods to the carrier arm and pushrod assembly. Also, this arm accepts the much more robust 12mm id pivot bolt bushings used up to '95 and the '85 - '86 idler roller. The sensor wire from the arm can be secured to the center cover by a shop made pin/stud contact , so the early 16v center cover will do the job.
The guide for the TB at the crank was updated to a roller in ~ '82: to do this update, either change the back cover, or carve away with a box knife to get the roller assembly to fit where the guide piece had resided
That's pretty much it ... to go to the S4 level, another tensioner with a displaced centerline (~7.4mm) to match the TB center was used, so a different carrier arm, pivot stud vs bolt, stud to pump brace, idler roller, double roller crank idler, and waterpump must all be changed. IIRC, the center cover also, so the investment increases for modest gains ( if any).
To have the alarm functional, the relay mentioned is the simple way to shunt power to a light when ground on the solenoid is lost ..... a 'reverse' relay.
As I get ready to push the enter, noted that this is post #3000
: help needed for addiction ....
12-19-2005, 10:25 PM
#9
Under the Lift
Lifetime Rennlist
Member
Lifetime Rennlist
Member
Garth:
To you this is pretty simple, but that is a LOT of hardware to change, even not going S4. Finding all of the parts used short of getting somebody's blown engine, would be hard, and getting them new would be pretty expensive, especially for the tensioner body and arm. You could upgrade to the later tensioner and monitoring system without doing all the gears (to accomodate the later round tooth belt), right? Although the gears are not that expensive and often need to be replaced anyway.
To you this is pretty simple, but that is a LOT of hardware to change, even not going S4. Finding all of the parts used short of getting somebody's blown engine, would be hard, and getting them new would be pretty expensive, especially for the tensioner body and arm. You could upgrade to the later tensioner and monitoring system without doing all the gears (to accomodate the later round tooth belt), right? Although the gears are not that expensive and often need to be replaced anyway.
12-19-2005, 10:54 PM
#10
Nordschleife Master
Join Date: Sep 2004
Location: Not close enough to VIR.
Posts: 9,429
Likes: 0
Received 2 Likes
on
2 Posts
My 84 is interference and I'm happy I don't have the idiot light.
Bill, I think all that is really needed is changing the tensioner (per Garth below), tensioner arm, tensioner roller, idler, waterpump, and adding the electical stuff. Except for the arm and electrical, all of the rest should be replaced with a complete timing belt job.
Bill, I think all that is really needed is changing the tensioner (per Garth below), tensioner arm, tensioner roller, idler, waterpump, and adding the electical stuff. Except for the arm and electrical, all of the rest should be replaced with a complete timing belt job.
12-19-2005, 10:58 PM
#11
Rennlist Member
Originally Posted by Bill Ball
Garth:
To you this is pretty simple, but that is a LOT of hardware to change, even not going S4. Finding all of the parts used short of getting somebody's blown engine, would be hard, and getting them new would be pretty expensive, especially for the tensioner body and arm. You could upgrade to the later tensioner and monitoring system without doing all the gears (to accomodate the later round tooth belt), right? Although the gears are not that expensive and often need to be replaced anyway.
To you this is pretty simple, but that is a LOT of hardware to change, even not going S4. Finding all of the parts used short of getting somebody's blown engine, would be hard, and getting them new would be pretty expensive, especially for the tensioner body and arm. You could upgrade to the later tensioner and monitoring system without doing all the gears (to accomodate the later round tooth belt), right? Although the gears are not that expensive and often need to be replaced anyway.
Yes, the HTD belt and gear upgrade is entirely independent of the tensioner, and can be done or not.
The tensioner body with matching arm is key to the upgrade, and often can be located used for reasonable cost, as can the early cam drive gears.. All of the idler and crank rollers can have fresh, standard sized sealed bearings pressed in without special tools ( ~$5-8 each), and the tensioner roller is the same for all years. A tensioner body rebuild is ~$40 ... again, same for all years. The updated rear cover is not necessary, etc .... so it can be as little as locating a used tensioner and carrier arm *: the rest of the costs are those incurred in a routine R&R when doing a belt change.
* have found rebuildable tensioners & arms for <<$100
