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Questions tagged [valve]

Refers to engine intake or exhaust valves.

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Is it worth it to try to solve a valve problem on my old Volvo?

I have a 1996 Volvo 850 which has some kind of serious valve or piston problem. The mechanic said that there is zero compression in cylinder 2 (its a 4-cylinder GTS). He said he could not see anything ...
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1answer
70 views

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 ...
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Bent push rod, valve bent as well?

so i finally got around to opening up the head of my lawn mower and found out why it wasnt running. the intake push rod is bent. and the exhaust is straight. obviously my valves were way out of spec ...
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1answer
80 views

Benelli TNT 150 has how many valves?

I know my question is out of topic but could anyone tell me if Benelli TNT 150 has 4 valves or 2? Internet wasn't helpful. I am also confused between Benelli TNT 150 and TNT 15. Thanks EDIT To make ...
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1answer
79 views

Will a hole in flex pipe or exhaust cause burned valves?

I bought a 300 5.7 hemi. It has a hole somewhere in the exhaust. I suspect flex pipe. Old owner said he's been driving it like that for a while. It's really Loud! Will it cause a burned valve? I will ...
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1answer
161 views

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 ...
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1answer
36 views

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 ...
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1answer
235 views

Exhaust backfire on reductions/engine braking

I've recently acquired a 2001 Corsa Milenium (a Brazillian saloon version of the Opel Corsa B, with a GM 8V 1.0 MPFI engine). It has a performance air filter (which I plan on replacing with the ...
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1answer
287 views

Gas leaking from this tube,wondering what exactly this tube is

Hello, I'm fairly new to mechanics of motorcycle(riding for 2 years but never tried to repair it myself till last month). As I noticed I am using way more gas than usual and there was gas odor, then ...
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0answers
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Do valve adjusters ever go bad?

Do the top screw parts of the valve adjustment screw ever go bad? Doing a valve adjustment on 2005 Honda Odyssey. On a few valves, the part that you adjust does not feel right. It is either too ...
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1answer
104 views

Buick Rendezvous 3400 SFI no start when warm/hot

The problem is that when the engine is warm/hot it does not want to start. I can crank it all day long but it doesn't even sputter. Things I checked: -Fuel pressure -Spark (It seems weak? Has an ...
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1answer
190 views

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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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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2answers
416 views

Burnt valve diagnosis with broken radiator

The radiator on my 2001 Volvo v40 blew on the highway last week and the engine overheated. I had it towed to my shop, and let them know the situation, and expressed concern of engine damage because ...
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0answers
114 views

Toyota Sienna 1999 - Valve Stem seals

I've got a 1999 Toyota Sienna handed down to me from my family. For the past year, on startup a heavy plume of blue smoke would come out. Researching online, I've read it's related to valve stem ...
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1answer
65 views

valve adjustment 1984 F150 302

stock cam, hydraulic lifters. when removing the lash and finding the start of "tension" on the push rod how far should the spring loaded part of the lifter depress before you add the final 1/2 - 3/4 ...
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1answer
1k views

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 ...
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2answers
265 views

How come only one piston was damaged?

This is a 2007 Dodge Caliber 2.0 CRD (which uses a VW Golf 5 TDI engine). The valves on only 1 piston have come into contact with the piston, causing chaos in that cylinder. The other three are fine. ...
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0answers
295 views

Valves calibration vs fuel economy

My new hobby car (Fiat 126p, 2 cyls air cooled, rear mounted) is not doing correct fuel economy. Spark plugs looks ok. Fumes, at cold start are black but as it warms up, it looks ok. The only ...
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1answer
6k views

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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3answers
470 views

Can I add a gasket to my exhaust valve to reduce leak and increase cylinder pressure?

So I have a single cylinder diesel engine. We do not use it to produce power (it is operated by an electric motor) but to measure the pressure at low rpm (100-200). The volumetric compression ratio is ...
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1answer
59 views

Proper electrical cable disconnect procedure for purge valve?

Attempting to replace a canister purge valve (pictured) Some of the instructions I've read say to disconnect the battery terminals prior to remove the electrical cable and removing the valve. That ...
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4answers
2k views

Necessity of checking valve-clearance on 1 cylinder GY6

Engine-valves usually get tighter as they're used. The symptoms of engine-valves that are too tight, are as follows: Bad fuel economy Difficult to start Stalling idle The manual for my scooter ...
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0answers
2k views

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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1answer
536 views

Probably Tappet noise in my brand new yamaha fz fi

Little Tappet noise from my brand new bike i.e yamaha fz fi india. Svc guys told me it require valve clearance adjustment. My question is, is it ok for brand new bike to adjust valve clearance on its ...
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1answer
152 views

If I'm lapping valves do I need to replace piston rings?

I just removed the head and am lapping valves because of timing problem. If I'm lapping valves, do I need to replace my piston rings too or not? Car: 2010 Passat CC 1.8 TSI, 100,000 km
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1answer
109 views

Can I remove the valve cover to retrieve the extension with 8mm socket that fell into my engine? [duplicate]

I dropped an extension with a 8 mm socket attached into the plug hole. I started the engine for like five to 10 seconds to see if it blew out. I read that starting the engine was an huge mistake. With ...
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1answer
1k views

Hole-in-One. Small extension and socket fall into valve

I am very poor so I work on my house/SUV (2002 Ford Expedition) myself. Recent misfires had me changing coils and spark plugs. Well, everything is going fine until my extension comes off my socket ...
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0answers
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Burned valve Ford Focus 1.6 16v (2010)

and thanks in advance for your help. I have Ford Focus 1.6 16v 2010 model bought brand new.I"v had installed an LPG gas system "Lowato" from the beginning almost,and never had any problems with the ...
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1answer
150 views

Is there clearance for the valves to go, in case of busted belt on a C4 1.4 V16 2005

I just broke down and had to get pulled. Car stopped moving mid drive and wouldn't start, the starter would turn but make a strange higher-pitched noise than the usual one. The guy offered to ...
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0answers
81 views

Light abrasion on the valve stems - is the outlook gloomy?

Background I'm rebuilding my LS1 Chevy. The cylinder heads came back from the machine shop fresh with a 5-angle valve job and mechanically-lapped valve faces and seats. What concerns me is the ...
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4answers
396 views

Lapping valves by hand - does the compound have to be cleaned off?

I'm hand-lapping valves on the LS1. This is probably a silly question, but I just wanted to confirm that I have to wipe off the lapping compound prior to the hydro test.
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1answer
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Should I be concerned about eccentric valve rotation?

Yup, it's that infamous Exhaust Valve #3 again (that "6" is a misnomer). It's now back from the machine shop, with a freshly-cut valve face as part of a 5-angle valve job. Now that the valve and ...
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3answers
366 views

How does excessive undercutting of valves make an engine less streetable?

I don't understand a claim made by Jafro's machinist in this video (around 26:00): (Jafro inspects undercut valve) Machinist: You drive it on the street too, don't you? Jafro: ...
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1answer
78 views

Would using a cooler plug help or even prevent this level of exhaust valve damage

As I posted in a related question: Help me diagnose the cause of this intake valve burn Here is depicted an instance of its EXHAUST (not intake) valve burn, the key note being there was a head deck ...
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2answers
122 views

Is this valve toast or could I possibly salvage it without tearing into the engine?

I have a 2010 Mustang GT with 4.6L engine that started making a ticking sound which at times is fairly loud. The sound is much less obvious at cold start but becomes apparent after it gets hot. The ...
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1answer
593 views

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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1answer
2k views

This valve is pitted - what options do I have?

This is that infamous Exhaust Valve #3 after cleanup. The cylinder had a history of fuel/spark-related misfires. As the images show, the lip of the valve is pitted. Here is the back of the valve. I ...
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1answer
889 views

Do I risk damaging the valve seat if I lap this valve without removing carbon build-up?

This valve is from my LS1 (Exhaust #3). It's suffered from a lot of carbon build-up due to a history of fueling/spark problems. I've tried cooking it in ethylene glycol. I've tried using abrasion ...
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0answers
105 views

Overfill oil on 1.5 Liter VTEC-e Civic 1995

I have a 1.5 Liter VTEC-e Civic 1995. The valves are noisy if I fill oil up to the manufacturer recommended level. But if I overfill by a quart the engine and valves are much quieter. Is this ...
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1answer
81 views

Why a two-lever valve spring compressor?

I just purchased a valve spring compressor that has a lever on both ends, similar to this one: What is not clear to me is the advantage of having this two-lever setup. What does it have over the ...
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0answers
80 views

Identify Valve Noise RECORDING

What's that sound? Sorry a little long (15:00) see notes below for TLDR. https://drive.google.com/file/d/0B4e9w0OOuGinSVhqMVM5OHQwZ3c/view?usp=sharing Note good power and smooth shifting at 3m10s ...
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2answers
417 views

Seat Toledo engine stalls when warm

I have a 2001 1.6 16v Seat Toledo. Short story: My car randomly stalled when the engine warmed up to operating temperature and I could not restart until it cooled down. A mechanic cleaned the ...
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2answers
2k views

Lapped valves still leak but slowly

Background I did some work on my engine's head valves and their seats. This is a very old engine with very old/abused/invented/adapted parts, etc. Both the valves and seats were in pitiful ...
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2answers
392 views

Can leaky cylinder explain oil loss to burning?

One out of the 6 of my Toyota Tacoma cylinders is mildly leaking, as indicated by a cylinder leakdown test. While other cylinders are leaking only something like 5-10%, this one leaks about 20% of the ...
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2answers
96 views

Are there any downsides to the Coates valvetrain?

There was a lot of buzz around the Coates valvetrain circa 1995. (Animation is too good to miss) Two decades later, I still don't see mass adoption of this "revolutionary" technology. So what gives? ...
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0answers
116 views

Ticking after much engine work

This question is a follow up to this question: 1994 Honda Accord EX (F22B1) - Valves still making a ticking noise Work I've done Replaced head New valves, new seals new gaskets verified different ...
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3answers
4k views

Preventing debris from falling in engine while changing valve cover gasket

I am about to change the valve cover gasket on a 2002 Ford Focus SE Wagon with the DOHC Zetec engine. I have never done this kind of thing before, and although it seems simple, I am concerned after ...
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1answer
64 views

Where do you install cylinder heads, camshafts and valves in different engine types?

I am trying to learn about engines, so my question is where do valves, camshaft etc go inside different engines? I see different engine have them in different places, base on if the engine is a inline,...
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1answer
442 views

Tyre Valve Pin Too Far In

I just bought a second-hand car, and when I got it home I tried to check the tyre pressures, with a simple mechanical pressure gauge like this, which I've used for years on previous cars with no issue....