Thank you, Nevada. If it comes to it, I will most certainly change the gears also, but I doubt that it will come to that.
Effects of a worn or stretched timing chain
The timing chain is comprised of a series of links in the chain ā similar to those found on a bicycle chain. The links move on the toothed sprockets which are located on the ends of the crankshaft and camshaft and are responsible for opening and closing valves in the cylinder head and moving pistons and connecting rods in the combustion chamber. The timing chain can start to stretch and wear over time, which will cause the engineās timing to be inaccurate [and produce a few warning signs.
- Engine misfires or runs poorly ā NOPE
- Metal shavings found in the oil ā NOPE
- Engine wonāt start or fails ā NOPE
4 . Check Engine Light is on ā NOPE
5 . Engine rattles while idling ā NOPE
Signs of a Stretched Timing Chain
- Backfiring ā NOPE
- Power Loss ā NOPE
- Noise from Timing Cover ā NOPE
Crankshaft Test
A simple test involving the amount of degrees you can move the crankshaft can also be a useful way of determining if you are having trouble with your timing chain. Remove the distributor cap, and turn the crankshaft, clockwise. When the rotor starts moving, stop turning the crankshaft, and read the degree meter. Note of where the rotor is, and turn the crankshaft, counterclockwise, until the rotor moves. Read the degree meter, and see how many degrees the crankshaft moved. If it is more than 10 to 15 degrees, your chain is too loose.
Nothing at either site about overheating or high combustion chamber temps. And my timing chain is only 7 degrees loose.
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The point is, if the chain is worn, the gears are, too. So itās already ācome to thatā.
Yes, I agree that the chain and gears all need replacing if the it comes to that. Whether or not it has come to that has not been determined with absolute certainty. What has been determined with close to absolute certainty is that there is 7 degrees of looseness in the timing chain, as determined by the distributor rotor observation method, and that a site that tester used to prove a point says that āIf it is more than 10 to 15 degrees, your chain is too loose.ā
So excuse me if I donāt just jump on testerās suggestion to go right out and change the timing belt and gears on this truck, which starts up within one second of cranking, idles smoothly and has plenty of power at all speeds. I sure hope I didnāt hurt his or anyone elseās feelings.
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You glossed over #4. Your check engine light isnāt on because itās a dinosaur. The article is assuming you have a vehicle from this century with commonly available advanced diagnostics - OBDII. Yours does not, it can only detect rudimentary issues.
If you bothered to read further, it says-
A stretched timing chain contributes to poor engine performance and increased emissions,
The point is that there are degrees of failure. Yours is in the early stages and so may not display ALL or even most of the tell-tale signs.
A healthy dose of skepticism is good. Your replies border on arrogance. You may not realize that, I know a few people who havenāt a clue in this regard. But the most dangerous combination is ignorance coupled with arrogance. Frankly, I am surprised people continue to try and help. Most people here are helpful in spite of the responsesā¦
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First you are making the stretch, no pun intended, that a stretched timing chain causes high combustion chamber temps, and thus increases NOx emissions simply because it causes poor engine performance, and may cause a check engine light to appear. I have no doubt that this condition can increase HC and CO emissions, due to incomplete combustion, which would actually lower combustion chamber temps. And as much as you denigrate this ādinosaurā it does have a pre-OBDII onboard diagnostic system that can be checked with a Miller Tool C-4805 Diagnostic Readout, commonly referred to as a ābreakout boxā, which I have right in front of me, and when used, it shows no trouble codes set. And what is most important, you seem to be ignoring what I wrote about the engine performance on this truck. It is superb, which is why I do not want to surrender it to a failed emissions test.
I have concluded phase one of my attempt to remove the insulating rust layer from the water jacket. The first chemical I used was spent, and I flushed it well and introduced the second chemical, which I shall leave in until it is also spent. If I am feeling particularly determined at that time, I may pop out a freeze plug to check the results. Or maybe first I will remove one of the small drain plugs on either side of the V6 block, which is much smaller that a freeze plug, but much easier to remove and reinstall.
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Yes, I approach that line, but make every attempt not to cross it, very astute of you to notice. The same can also be said of some of the replies I have received in this thread, which is completely opposite to the spirit of the actual Car Talk radio show. I have never heard either of the hosts demand recognition for their years of experience, or berate a caller for not accepting their opinion. In fact, they were the first ones to admit that they may be wrong, and their self-deprecating banter is one of the things that made the show so endearing for so many years.
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Just read up on water/antifreeze ratios. I have been using 50/50, like any good schoolboy would do, but then I read that antifreeze is no where as good as pure water when it comes to transferring heat, and that as little as 10% antifreeze is enought to provide anti-corrosion properties. There are also anti-corrosion and lubrication additives that can be added in place of, or in addition to, antifreeze, especially in hot climates that never see freezing. So after this current rust destroying chemical does itās work I will take it down to be smogged using only water, and perhaps one of the above mention additives. I canāt wait! I some point I will give up if it doesnāt pass, and sell it to the govt for $1500, although I will be sorry to see it go.
You are looking for problems where none exist. Just about every car on the road runs fine with 50/50 water/antifreeze mix. If your truck overheats, itās not because of the mix, itās some other problem. This is doubly true regarding your emissions test problems.
Donāt forget that antifreeze not only lowers freezing point, but also raises boiling point. Running straight water or a weak antifreeze mix may increase chance of boilover.
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Water boils at 257 degrees with a 15 lb cap on the radiator, coolant raises the boiling temperature to 265 degrees. Race cars use water.
Ah, George, I could kiss ya!!! I applied vacuum while at idle and the engine did - not - blink! I applied vacumm with the engine off and noted the EGR valve responding well. Kept it open and stuck a wire into the exhaust port and saw the wire at the opening to the intake manifold so the EGR valve is in great shape, as is the vacuum signal from the carb. I turned the engine on with the EGR valve removed and exhaust is pulsing strongly out of the exhaust port. I popped the carb to see if I can see the wire I shoved into the EGR intake port inside the intake manifold, but it does not follow a straight line apparently, so I need to look at the underside of the intake manifold to give me a clue which way to direct the wire to break up whatever obstruction is blocking the exhaust from entering the air/fuel mix, so I am off to RockAuto to look at pictures. Thank you thank you for bringing that up!
Applying vacuum to the EGR valve is a test you should have performed in the beginning.
Shoulda woulda coulda, but here we are. If we all did everything when we should have we would all be richā¦ maybe some of us are, but I aināt. Iām just happy to be where I am, and not where I was.
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Just poured some lacquer thinner down the intake port where the EGR valve mounts. I filled to the top and it just sat there, indicating a clogged passage. Then I stuck a 14 gauge copper wire into the hole and worked it around and pulled up some black gunk. The wire was coated with it. Getting ready to pour some more lacquer thinner in there and continue to poke at it with the wire. I also have some Lucas Upper Cylinder Lubricant which I may try. But I have definitely found the problem, clogged passages from where the EGR valve mounts to where they exit on the intake manifold just below the carbā¦ and the cooling system is as clean as it has been in decades!
Race cars also use much higher pressure radiator caps with stronger hoses and radiators.
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The stock class at the local circle track must use stock type parts and no cars are allowed to use coolant.
Occamās razor strikes again.
Buy this
Use the snake on the bottom
Mount it in your drill and set it up for REVERSE
Let it pull it itself through slowly, while itās busting up the carbon
Thanks for that, db. In my arsenal I found a small diameter steel snake screwed onto the end of a longer nylon snake used for pulling wire through conduit. Unscrewed it and used as you suggested, in a drill. The EGR port enters the intake manifold and splits in two to enter the air/fuel mix just below the carb, fore and aft. It is gunked in there good, but, in the immortal words of Chief Dan, I will not fail to endeavor to persevere.