Questions tagged [valve]
Refers to engine intake or exhaust valves.
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Will alien component found in new engine tear down effect valve behaviour?
OMG, I might have found the cause of a misfire in cylinder 1 that has been the bain of my life on and off for 3 years.
I have a 1979 sherpa van with an austin/leyland "o" series engine. The ...
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Is it possible to test an exhaust system for a restriction without dismantling it?
I've had an overheating problem with a new/other engine (1991) for 3 years now. Some time back I discovered that there was a misfire on cylinder 1 and maybe an intermittent misfire on cylinder 4. I've ...
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Astra h engine oil consumption
My 2005 Opel astra h (engine code-Z16XEP) has developed some oil loss issue. During autumn months while I've been only city driving, it has consumed very little oil in comparison of what it had ...
CommunityBot
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Searching for poor burn problem. How to know if valve guides are worn?
I have a Chevrolet 2008 suburban 1500 v8 5.3L, and am looking for a problem that dirties the spark plugs and causes stumbling idle especially when cold. I am suspecting the valve guides are worn, ...
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Misfire! Does good compression mean there are no valve issues?
I have a new old stock sherpa "O" series petrol engine 1991 that I installed 3 years ago. I have a misfire on cylinder 1 (detaching spark plug lead makes virtually no difference to the ...
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How to set cam timing from scratch for Honda RFVC, DOHC, four stroke?
I'm doing a full engine rebuild on an Honda GB250 clubman, RFVC & DOHC four stroke.
I would like to know how to set cam timing from scratch?
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Will leaking valve seals harm an engine?
I have a Nissan VK45DE engine with some oil consumption issues that I think are leaking valve seals.
What harm will come to an engine if used long term with leaking valve seals other than the ...
CommunityBot
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Tapping engine noise, but only with load and only for short time
2003 Toyota Rav4. 4 cylinder, 145k miles. Recently started making a ticking noise. Noise only happens on startup and for about 15 minutes and ONLY when under load. So, start the car and fast idle ...
CommunityBot
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Flathead 8RT stuck valves — how to free 'em up?
I bought a '42 SnoGo last fall (with a newer flathead in it, an 8RT) that had sat unused for some time, at least fifteen years.
Well, you just can't do that here in Alaska and hope to get away with it....
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Why is one bank of valves much more dirty than the other?
I'm replacing my valve cover gaskets because they are leaking. I noticed a significant difference between the valves in the front and rear banks. The front ones look quite dirty while the rear ones ...
CommunityBot
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Camshaft valve clearance and fuel consumption
Does the clearance between the camshaft and the top of valve tappets (AKA lifters AKA shims) affect fuel consumption? I am asking because it seems to me like the lesser the spacing, the more the cam ...
CommunityBot
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Valve cover gasket; Torquing the cover
I am taking notes on the proper installation of a valve cover gasket. I plan on using Permatex Ultra Black RTV silicone in the process.
One suggestion I read is, after applying the gasket, silicone ...
CommunityBot
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How to resolve P0456 OBDII code?
What 3 things and in order can I DIY for p0456. Hard start after fueling every time and irregular idle when stopping at lights. P0456 and no other indicator lamps coming on. Didn't replace gas cap.
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Check emission system displayed on dashboard display
For the last week it has been extremely cold where I live (varies between -27 to -33 degrees Celcius). Is it possible for a fuel cap check valve to freeze open?
Last night leaving work the display ...
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Possible Top end or VVT replacement required? 75dB+ knocking from engine top end - 2018 - Nissan Pathfinder
First the link
Hello,
I have a 2018 pathfinder with a reasonably loud (i'm estimating it at over 75dB standing about a meter back from the front of the vehicle). The sound seems to be coming from the ...
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Valves in pizza box fell out does order matter if lapping
I had my valves numbered in a pizza box for lapping and i lifted the pizza box up the wrong way and every valve fell to the floor. i can tell intake apart from exhaust easily because they look ...
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Why when I turn the front wheels by hand, the crankshaft doesn't rotate?
I'm after head gasket replacement and I'm trying to adjust valve clearance.
2 wheels of a fwd 1995 Renault Twingo are lifted off the ground, the engine is in gear, but the crankshaft doesn't turn ...
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Briggs & Stratton 33R877 Engine Problem
May I please receive help in solving an engine problem? I have a Briggs & Stratton 33R877 engine (ride mower), and it is blowing air out of the carburetor. Here is what I've done so far:
Piston ...
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Burnt valves, '08 Mercury Mariner 3.0 V6, similar to Ford Escape
Seeing if anyone else has ran into this problem on a Ford 3.0 V6? It's an '08 Mercury Mariner, 150K miles. Well maintained. High quality synthetic oil used in engine. Almost if not the same as a Ford ...
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Adjacent exhaust valves in a cylinder head
There are some engines in which you can see two adjacent exhaust valves in cylinder head. The following head (Chevrolet Small Block) is an example:
Is it true that this particular head design causes ...
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Initial reassembly valve leak to be overcome by breaking in
I lapped my valves and got good results testing both off the engine (pouring alcohol in intake/exhaust chambers and waiting to see level unchanged) and on (cylinder leakdown test). However, as soon as ...
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Stuck valve in lawn tractor Briggs & Stratton OHV
My John Deere LA120 lawn tractor has a Briggs and Stratton 21HP OHV engine that quit suddenly. Bad gas was my first guess. Along the way, I discovered a leaky fuel pump. So far, I have now replaced:...
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Formula 1 valve trains
There was a statement in a post regarding Formula 1 valve trains being pneumatic or magnetic. Are there valve trains driven magnetically or pneumatically that are on the market? When did they start ...
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How do splash lubricated horizontal crankshaft engines lubricate the valve mechanism?
In many small engines, splash lubrication is used unlike in cars which always have an oil pump.
I understand that when the small engine is a vertical crankshaft one like in lawnmowers, where the ...
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Do carburetors protect intake valves from carbon deposits?
For a long time, most car engines were using multi-point port injection that sprays fuel directly at the intake valves. Today, engines are increasingly commonly direct injected. A problem of direct ...
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Do straight/short pipes burn out valves?
I have heard that straight/short/custom pipes can burn out valves on an engine. However, with a 4-cylinder Ford Model A engine, I have been told this is not the case because it has such low ...
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How much should you clean dirty pistons and valves when you aren't removing them?
I took the heads off so I could get some broken exhaust manifold studs out and retap (actually I was advised to use a Heli-Coil instead so doing that) one of the other stud holes.
The piston heads and ...
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When should I suspect that valves are not sealing
I just lost an (old, 230K miles) engine with no compression in two cylinders. It had been drinking oil liberally for a while, but just prior to this failure, had begun seriously drinking oil (6QT per ...
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Choosing the best timing marks
This question is somehow related to my previous question here:
Compression of valve springs and camshaft rotation
In that question, I asked about the pattern of camshaft rotation and how valve springs ...
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Compression of valve springs and camshaft rotation
As you know, in most cars it is not easy to turn the intake or exhaust camshaft by hand. You probably need to use both hands, grab the cam sprocket and apply a lot of force to rotate them even with ...
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How to interpret "crankshaft adaptation inlet Grad KW" value?
I'm trying to understand the meaning of this value and the implications of it being over the 120 limit.
Do you think you could help me out with some thoughts about it?
I think it should say "...
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Testing valve grind job that previously leaked
I had a leaky intake valve so I took that cylinder head off to grind it. Before grinding, I tested that it was indeed leaking and that the other two cylinders in the head did not by setting it on ...
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Lapping valves with a drill
I think lapping valves using one of those suction cup sticks is hard and there must be better ways.
So here is what I was thinking. I was thinking to get a really thin (medical or engine) hose that ...
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Reliability of water test for valve seal
I took my valves out, cleaned and lapped them and put them back together. I also put new valve stem seals. At least on one side of my V6 Tacoma.
I performed several water tests to check the seal of ...
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Should I lap my valves if I have easy access?
Now that I have my cylinder heads out of my V6 Tacoma, I am considering taking the valves out to inspect them in case they are bent or whatever and grind them. There is no symptoms of valves ...
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Are valve guides normally reusable?
A valve assembly diagram from my Tacoma FSM designates valve guides as non-reusable.
I was wondering if that is just a CYA or really the case.
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What keeps valve stem seals from dislodging from valve guides?
A valve stem seal, which prevents oil from the camshaft case from penetrating into the combustion chamber, is mounted on its valve guide simply by fitting it on with tension. Yet it endures probably ...
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Reusing valve stem seals
I just lapped my valves on a cylinder because they were leaking and reused the stem seals. Should I put new stem seals or is it okay to reuse them?
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Effects of intake valves leaking
I just measured cylinder leakdown rates on my 2007 Tacoma V6. 5 out of the 6 cylinders had retention rates of 75-85% (leaking 15-25%) but my cylinder 4 (left engine bank in the middle) was leaking ...
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Lubricating inside valve tappets/shims
Toyota engines come with tappets to shim between the valve rods and the camshaft. They look like small cylinders and are about the size of 2 oz shot glasses.
When installing them on top of the rod ...
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Minor discrepancy in valve clearance reading
I started my engine work on a V6 Toyota Tacoma 3 mohths ago and continuing now from where I left off. Back then I did a valve clearance measurement on all the 24 valves with all the timing chains on (...
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Correct installation of hydraulic valve lifters
I was doing some research about removing and installing hydraulic valve lifters. I watched some videos on Youtube and found this one quite informative. However, there are a few questions I should ask. ...
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Valve lifter replacement based on clearance check
Since I have the valve covers off on my 2006 Tacoma V6, I decided to do a valve clearance check. The manufacturer recommended ranges are:
TYPE
MIN
MAX
IN
0.006
0.010
EX
0.011
0.015
meaning the ...
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Turning crankshaft specific angle
To check the valve clearances, the Haynes manual for my Tacoma (2006, V6) says to first set the first cylinder of the firing order in TDC, do a sequence of valves, then turn the crankshaft 2/3 turn (...
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Can too much space between valves and camshaft cause oil in cylinder?
My 2006 Toyota Tacoma v6 is losing profuse amounts of oil although it runs just fine after adding more. I did a comprehensive overhaul several years ago and tuned the valves (ground them and ...
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Less oil on certain valves than others
I've got a 1986 3.8l 6-cylinder mustang. I've been hearing a ticking underneath the driver's side valve cover, so I took it off. I didn't see anything wrong so I started the engine sans valve cover. ...
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What are the pros and cons of valves being placed in a line vs valves being placed side by side in 2V engines?
As you can see in the picture below the valves in this ferrari dino dohc 2 valves per cylinder v6 engine are placed side by side and not in a row. And as you can see here in the other picture below ...
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Which part of the valve stem do i need to replace?
I cant tell which part is messed up (I hit it with a hammer accidentally while trying to get my tire off). Do I need to replace the whole system, or just the body?
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Help me diagnose the cause of this intake valve burn
I would like some help diagnosing the probably cause of this intake valve burn as seen in the picture.
167fmm engine.
229cc OHV push rod type.
Now here is the rub.
this is engine originally 9:1 CR, ...
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Are valve shims re-usable?
I'm in the process of re-shimming the valves on my 1994 Suzuki Katana 600. For the valves where I need to replace the shim, should I save the old shim I removed, or is it considered a disposable item ...
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