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24 votes
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What is crankshaft grinding and why is it done?

Grinding a crankshaft is a process of removing material from the journals in an effort to refurbish and reuse an expensive, yet vital component of an engine. It is usually done during the process of ...
Pᴀᴜʟsᴛᴇʀ2's user avatar
11 votes
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How would a camshaft start moving during a cold start?

Crank shaft has a pulley or a sprocket at the front end, which turns a cam shaft/shafts through a cam chain or cam belt (timing belt). 1 turn of a cam shaft = 2 turns of a crank shaft. At the other ...
Arturs Bolsunovskis's user avatar
10 votes

What is crankshaft grinding and why is it done?

A crankshaft wears with use. After a lot of miles, the play between shaft and bearing becomes too much. The more play, the lower the oil pressure, the worse the lubrication. And then it wears out even ...
Bart's user avatar
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8 votes
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Can I run the engine for a short amount of time with a loose crankshaft pulley bolt?

tl dr: You possibly could, but why not just do it the right way? Get the right tools for the job and do it right from the get go. This way you won't have to worry about anything falling off while ...
Pᴀᴜʟsᴛᴇʀ2's user avatar
7 votes

How to lock crank shaft while torquing central screw?

There are a few different ways I can think of to do this: If the vehicle has a manual shift transmission, put the transmission into the highest gear, then set the parking brake. The torque provided ...
Pᴀᴜʟsᴛᴇʀ2's user avatar
7 votes
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What is "seal saver"?

I see two possibilities: He just putted some leak-stop additive in the engine oil. That is some additive that is intended to stop an seal leak by miraculously thickening the oil around the seal area ...
Martin's user avatar
  • 8,458
7 votes

How To Test New Timing Chain Before Engine Closed?

For a four-stroke engine you need to rotate 2 turns of the crankshaft to get to the same position.
Solar Mike's user avatar
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6 votes
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How are crankshaft crankpin journals ground?

First, it's not spun on a lathe to make it round again, at least not the typical machine lathe you'd think of. It's a machine which has a huge grinding wheel, thus the reason we call it grinding a ...
Pᴀᴜʟsᴛᴇʀ2's user avatar
6 votes

Can I run the engine for a short amount of time with a loose crankshaft pulley bolt?

Crack it loose and then have them re-tighten to 70 lbs, this way you can remove it when you get home without risking it coming loose during the drive.
Moab's user avatar
  • 7,990
5 votes

Pivoted curved-path piston engine

The only curved bore designs I am aware of are toroidal I have been unable to find a match to the drawing, not even close. I took a hard look at steam engines as well. Here is an example of a ...
DucatiKiller's user avatar
  • 32.9k
5 votes

How to lock crank shaft while torquing central screw?

An old trick for this is to remove a spark plug, then feed a length of string into the cylinder through the spark plug hole, leaving enough string hanging out to pull it all out when done. The string ...
CBRF23's user avatar
  • 536
5 votes
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Hand turned the crankshaft while in gear. Clutch damage?

It's fine I did a similar job on a 2003 model recently. I kid car. Luckily, I didn't have any bent valves to deal with. Turning the engine over with the head off and the car in gear won't hurt ...
DucatiKiller's user avatar
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5 votes
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A safe way to turn the engine without a crankshaft pulley tool?

Either use the tool probably with a crescent wrench since there is not much space unless you have the fans out and whatnot. Or get a remote starter like this one. Hook it up to the positive battery ...
Cc Dd's user avatar
  • 2,879
5 votes

Why does this mechanic change the crankshaft mark, during this timing-belt change?

The simple answer to this is that you can make any marks you want on the pulleys before you take the belt off. As long as you put the belt back on with the pulleys in exactly the original position as ...
HandyHowie's user avatar
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4 votes
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Oversize rod bearings question

You take the nominal diameter of the existing bearing and using the result of the plastigauge add / subtract to get to the diameter you need, then that gives you the amount of over or undersize ...
Solar Mike's user avatar
  • 34.6k
4 votes

Oversize rod bearings question

Realistically, if your rod journals are worn, you'll need to take it to the machine shop to have the crankshaft inspected and reground if it can be done. The machinist (or shop) will then figure out ...
Pᴀᴜʟsᴛᴇʀ2's user avatar
4 votes

Is it possible to just change the crankshaft and bearing and 1 connecting rod with out changing the heads on the vehicle

It is most probably possible to change crank and bearings, but to change the con-rod the piston has to come out so the head has to come off.
Solar Mike's user avatar
  • 34.6k
4 votes

Will it do any damage to the auto transmission if I manually rotate the crankshaft at Parking gear?

No, this will not cause any damage. Cars have the engines running while they are in park. Park is a selection in the ´box that allows the fluid to circulate without providing any drive to the wheels....
Solar Mike's user avatar
  • 34.6k
3 votes

Can I run the engine for a short amount of time with a loose crankshaft pulley bolt?

Well, you can ... so long as you don't have the same result as happened to a friend of mine. He was driving along when there was a sudden "clunk" and the ignition warning light came on. The obvious ...
alephzero's user avatar
  • 2,954
3 votes

Does it matter which side to turn crankshaft?

Not at all, in fact in some engine manuals, ignition section, they instruct to move clockwise up to TDC then counterclockwise before 10 degree mark, then again clockwise until that mark in order to ...
Aram Alvarez's user avatar
3 votes
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How to loosen the crank pully bolt with hand tools?

I'd written the same answer for another post, but it had to do with taking the fan loose from the water pump where there is a single large nut on the fan connecting it. The same graphic will work here,...
Pᴀᴜʟsᴛᴇʀ2's user avatar
3 votes

When switching off the engine, do the cam and crank shafts always come to rest in an initial state?

No. An engine stops where it stops because it is random when you turn the ignition off, and therefore there is no set place for it to end up at.
Pᴀᴜʟsᴛᴇʀ2's user avatar
2 votes
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Why won't my engine rotate?

It's been a while, but I finally took the heads off and many other things. The problem was, essentially, a "kink" in the chain connecting the crankshaft and the intermediate shaft (layshaft). I ...
Edward's user avatar
  • 2,857
2 votes

How to loosen the crank pully bolt with hand tools?

It depends on the design of the particular crankshaft pulley on your vehicle. Some of them have bolt holes specifically for this purpose; if that description matches yours, then what some people do ...
Cognitive Hazard's user avatar
2 votes

A safe way to turn the engine without a crankshaft pulley tool?

Pulling various suggestions together: Pull the spark plugs, once they are out the engine will not build up compression and turning it over will be much easier. It will also be easier to position the ...
dlu's user avatar
  • 14.5k
2 votes

A safe way to turn the engine without a crankshaft pulley tool?

As @Cc Dd said: 'pull all the spark plugs'. This is by far the easiest method i think. It requires the least effort and you don't need special tools, unless your plugs are hidden away somewhere very ...
Bart's user avatar
  • 2,954
2 votes

Why Tachometer shows idle RPM range instantly when closing the throttle and clutching

It's a bit hard to understand your question, but I'm assuming you're asking about the RPM jumping between idle and back toward 5,000 when you disengage/engage the clutch. When you start the throttle ...
raydowe's user avatar
  • 3,012
2 votes

Why Tachometer shows idle RPM range instantly when closing the throttle and clutching

From what I can understand, assuming the OP is curious as to why instantly pulling on the clutch the RPM goes down in a swift moment and not gradually? Simple: Inertia The reason for this is that ...
Shobin P's user avatar
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2 votes
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Measuring crank and rod journals

A very accurate way to mic your rod and main journals is to use a telescoping gauge set. They looks something like this set: The ends of the "T" are spring loaded and the end at the base of the "T" ...
Pᴀᴜʟsᴛᴇʀ2's user avatar
2 votes

2004 Mazda 3 stalls and bogs down on cold starts

... stalls and hesitates during acceleration after a cold start ... runs perfectly after 7-10 minutes of idling ... only error code I have is for an upstream O2 sensor heater control circuit. The ...
Zaid's user avatar
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