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New to the site. Been working on my truck and came across Erics videos, extremely helpful. I always appreciate how he explains things in easy to understand terms , not way over my head doctor language. I do have a question or situation really? Driving truck last week had a really bad sound, truck changed in power, idle, sound, everything. Made it home to see what it could be, well, here is the video i posted so i wont have to explain everything. http://www.youtube.com/watch?v=731TygPKnlA . I changed the tensioner and guides, got it all back together. It turns over but has a loud ticking or knocking sound, runs pretty ruff but holds idle. Watched your compression video and went out to buy a comprssion tester. Did that and found my #2 cyc has zero compression. 1,3,4 all are 164-180 dry , and 185-195 wet. Going to attempt a leak down test on that cyc. but i have to go buy the right attachment. the compression tool hose with fitting i have is proprietary and wont fit into my compression hose female end. boooooo 🙁 . Should i start to cry now, look at buying new truck, or spend whats left of my money on the lottery and hope i win big….????????? thanks all. Again greatly appreciate gentleman like Eric who take there own time or feel that itch to help others in there field of expertise. Thanks again.
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It sounds good to me…Congrats! Did you set the ignition timing with a timing light? Retarded timing could be causing your issues.
I forgot to mention i did a compression check after i got back from the test drive.
Cyl #1-118
Cyl #2-121
Cyl #3-120
Cyl #4-119
All dry test. But compared to the first compression test i did with the #2 cylinder at 0 compression, pretty nice. All other cylinders from first test before the repairs were 164-180. I havent looked this up but im hoping these numbers are better in the 120 range rather then 170 range. Also i used my little cheapy OBD2 reader and got no codes but there were a few blinking I/M monitor status icons. They were the “O”,”C”,”E”,and “EV”. I tried to look this up but had no luck finding out exactly what those meant. :unsure: But I was pretty tired from lack of sleep.[quote=”wysetech” post=74869]It sounds good to me…Congrats! Did you set the ignition timing with a timing light? Retarded timing could be causing your issues.[/quote]
I didnt use a timing light. When i did the tear down i put it at TDC then i marked all the timing chains , the sprockets, and camshafts with a paint marker. I lined up all the marks when i put it back together, all while keeping it at TDC. I hope that is what you were referring too. But ignition timing? Im not sure. What is the best way to set ignition timing? With me not being a mechanic and all. :unsure: Would i have to buy a timing light to get it dialed in correctly?Check for vacuum leaks… Ensure all vacuum lines are installed correctly and have no cracks or splits…
As far as timing… If you have an adjustable distributor, ensure you time the engine properly using a timing gun on your marks on the crank pulley or damper (or wherever the timing marks are)… Every vehicle has its own timing instructions (look under the hood for them)…. Simply stated, it usually it involves setting the engine RPMs to a certain amount, blocking off certain vacuum lines, pointing the timing gun (after hooking up the timing gun pickup to the #1 cylinder spark plug wire) and point the gun to the pulley/damper mark (be sure to highlight the timing mark on the pulley or damper with a piece of chalk, they can get hard to read due to dirt and grime) and look for the mark to be illuminated… loosen the distributor lock bolt and rotate the distributor slightly to the left or right until the timing marks (illuminated by your timing gun) are lined up and lock down the bolt…. Easy work… but old school… LOL!!!!
-Karl
Thanks a bunch karl. I just looked under the hood and i have no sticker. boooooooo. But after replying to wysetech i felt someone slapping me in the back of the head followed by , “hey dummy, look to see if Eric made a video on ignition timing”. 🙂 he did, and i watched. So now i have an understanding what you guys are referring too. But for me to invest in a timing gun to time just my truck… I guess if i take it to a mechanics shop , what would i be looking at, around 60-100 bucks. Might be able to buy one for that . not sure. Ill have to give it a look.
I have no sticker but i do have a chiltons, and that mark you mention is on my crankshaft pulley, and its red which makes it very hard to see. So i like your chalk idea. thks.Before you take it in, look at your distributor to see if it CAN be adjusted… With Camshaft and Crankshaft position sensors as well as modern ECMs’ the adjustable distributor and use of the Timing Gun has gone the way of the Dodo….. Hence why only us old farts still remember anything about them (and that long forgotten thing called the carburetor!) 🙂
-Karl
I hate to rain on the parade and while the compression numbers are better than zero, they still flat suck to be honest.
Odds are if you perform a wet compression test those numbers will jump up and that means a piston ring problem.
I’m also fully aware that some manuals (both aftermarket and even a few factory books) may make a refeence to numbers like that as being acceptably fine. Those books are wrong.
Bluesnut does make some valid points….
Remember, a compression test should be done with a warm engine and a WOT condition…..
However, I have seen engines that should have the best compression at 212psi per cylinder perform and run fine at 150-160 per cylinder….
As stated, a wet test can diagnose for worn rings or cylinders…
The true test is how well it performs on a daily basis and what you require of this vehicle… Sometimes good enough is just….. good enough…
JMHO
-Karl
[quote=”ToyotaKarl” post=74876]Before you take it in, look at your distributor to see if it CAN be adjusted… With Camshaft and Crankshaft position sensors as well as modern ECMs’ the adjustable distributor and use of the Timing Gun has gone the way of the Dodo….. Hence why only us old farts still remember anything about them (and that long forgotten thing called the carburetor!) 🙂
-Karl[/quote]
Was just reading up on setting the Ignition timing . The Chiltons i have for the truck has a section on it. Have to disable the PCM first, but it does show that the distributor is adjustable.[quote=”Bluesnut” post=74877]I hate to rain on the parade and while the compression numbers are better than zero, they still flat suck to be honest.
Odds are if you perform a wet compression test those numbers will jump up and that means a piston ring problem.
I’m also fully aware that some manuals (both aftermarket and even a few factory books) may make a refeence to numbers like that as being acceptably fine. Those books are wrong.[/quote]So if i do a wet test and the numbers go up at all you would say its a piston ring problem? In general is a minor rise with a wet test expected or even exceptalbe? Maybe in percentages, like a 10% increase? I havent looked in my Chiltons or even on line at what the numbers should be for my truck, but after reading your post ill assume my numbers are low. As far as raining on my parade , not at all Blues. This is a huge learning experience for me, so any and all input is welcomed. If i have to tear the engine back down to replace the rings, its all good. I just did the head so i have that part down. Most of this is only possible because of websites like this and guys like yourself that are willign to take the time to point people in the right direction. Its very much appreciated.
I can’t remember for sure but the distributor should have a slot with a bolt through it where it bolts to the head. That’s where you adjust the timing.
Those compression numbers are off a tad. I would expect to see 140 to 160 PSI at least on that truck. Are you sure you have the timing chains lined up correctly as it only takes one tooth or chain link to kill performance.
If you have a vacuum gauge it might help a diagnosis somewhat.
Im pretty sure i have the timing chains lined up correctly. I matched all the marks i made with the paint pen. Its possible i could be off by a link i suppose.
I did look up with the numbers should be. Standard numbers for that truck are shown at 178. They also state a minimum of 149, with a maximum difference between cylinders of 14psi.Wysetech nailed it again…
Your compression numbers changing like that are a textbook example of timing being off….
-Karl
I have a feeling if the timing is off, that would explain the slight shutter of the engine at idle, right? It cant be off by much? If it was off by much would it still start and run like it was? Either way I have a small leak on the valve cover , so ill be pulling that off most likely tomorrow. Ill get it to TDC and check the orientation of the camshafts and see if it might be off slightly. Wys might be right, maybe its off one or two links.
A few pounds increase during a wet test would be normal but if the figure jumps from say 120 to 140 or 150 then there’s a ring problem.
Chiltons has a lot of inaccuracies so I never, ever rely on their publications. Some examples from a few of my Chilton books:
An electric fan on a Camaro should not turn on until 243 degrees,Oil pressure on a GM 3.8 should be 6 PSI at 1800 RPMs.
A compression reading of 115 on one cylinder and 150 on another is acceptable.
Connecting rod oil clearance on a small block Ford is .14. (Note the lack of a zero before the one.) 🙂
The reason for my emphasis on compression numbers is because I’ve been doing compression checks for 40 years even on low miles vehicles with no apparent symptoms or complaints. It was a standard part of any maintenance service or tune-up so my opinion is based on trends.
The smog era domestics of the 70s/80s often run around 160 or better (usually due to cam timing of that era) and with the old air-cooled 6:1 compression ratio Volkswagens, 120 is normal for those.
Most modern era engines, if everything is up to par, seem to run 180-190.
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