Timing Belt, Timing Chain, replacement, bad timing chain symptoms, help diagnosis repair

Suppose you knew there was a ticking time bomb under your hood. Would you keep on driving until it went off?

Although a broken timing belt won't kill you, it can certainly strand you in the middle of nowhere. (In these violent times that might just be a matter of life and death!) On some cars, this COULD DESTROY YOUR ENGINE: an expensive proposition indeed!

WHAT IS A TIMING BELT OR CHAIN? WHAT IS VALVE TIMING?

All current automobile piston engines have a camshaft and a crankshaft. The crankshaft transmits the power from the pistons as they move up and down and changes it to a rotating motion. (This is like the pedals on a bicycle changing the up and down motion of your legs to a rotating motion.) The crankshaft drives the CAMSHAFT, which opens and closes the valves in the engine. A camshaft has eccentric LOBES or CAMS all in a row: one lobe for each valve. This lobe presses on a cam follower or valve lifter which opens the valve.

For each cylinder, the camshaft first opens the intake valve to let in fuel and air to be burned. After this, the camshaft opens the exhaust valve to release the burned fuel gasses, which pass out the exhaust pipe. This all must happen at exactly the right time. This coordination of the crankshaft with the opening and closing of the valves via the camshaft is called Valve Timing or Camshaft Timing.

If valve timing is incorrect a valve can open at the wrong time and bend the valve!!

Timing Gears, Chains, and Belts

The camshaft is turned by the crankshaft. 3 different methods are used to connect them together.

THE TWO GEAR METHOD

This is the most reliable method. A gear on the crankshaft meshes directly to a gear on the camshaft. These gears last the life of the engine and almost never fail. The 2 gear method is used in big trucks and heavy equipment, as well as some cars. The only time I've seen a gear fail on a 2 gear drive camshaft is when a gear is made of nylon or fiber.

2) THE TIMING CHAIN METHOD

Although not as reliable as the gear to gear system, a timing chain still will last 80,000 to 100,000 miles or more before wearing out. As the chain stretches, however, performance will be affected. Also, on many vehicles the camshaft sprocket is made of plastic. When these vehicles are overheated even slightly this plastic can melt and the chain will skip teeth. The engine will stop immediately and will not run again until the chain is repaired. If a valve opens all the way at the same time as the piston comes up, it can bend the valve and possibly destroy the engine.

3) THE TIMING BELT METHOD

This method requires belt replacement every 40,000 to 60,000 miles. The camshaft sprocket is connected to the crankshaft sprocket by a toothed drive belt. This is becoming the dominant method. Over half of the cars on the road use timing belts. There are several reasons for this:
a) It's easier to connect the camshaft and crankshaft together with a belt when the camshaft is far away from the crankshaft (like with overhead cam engines).
b) They claim the belt is quieter. Belts are lighter than chains, and every ounce counts to the manufacturers.
c) It's much cheaper and simpler to make a belt drive engine than any other way.
d) When the belt breaks it can destroy the motor , so it increases new car sales or repairs.

A typical engine with a timing belt Timing belt with misssing teeth or cogs

These cars that almost always bend valves when the belt breaks: If you own one of these cars, replace the belt every 50,000 mile or... "YOU'LL BE SORRY!!!"

ALMOST ALL NISSANS
MANY MITSUBISHIS, CHRYSLER COMPACTS LIKE LAZER AND NEON (A lot of Chryslers have Mitsubishi engines)
FORD ESCORT WITH BLUE VALVE COVER
CHEVY SPECTRUM AND JAP NOVA
HONDAS WITH 16 VALVE 4 CYL. ENGINES

MOST HYUNDAIS
FIAT SPYDER AND SPYDER 2000 (FIAT SAYS 40,000 FOR THESE CARS, IF THEY'RE ANY OF THEM STILL AROUND)

I'm not sure there is a car that will NEVER bend valves, but the above cars almost ALWAYS bend one or more valves when their timing belt breaks.

The Gates Rubber Company website has a guide which tells which engines normally bend valves (interference engines) and which ones don't bend valves.

Here is a list of "known valve benders!"

PLEASE NOTE: Not all of these engines have timing belts. Some of them are chain motors. BUT ALL OF THEM WILL BEND A VALVE IF THE BELT OR CHAIN FAILS!!!

Source: www.rebuiltautoengines.com

ACURA
1986-89 1.6L Integra
1991-95 1.7L Integra
1990-95 1.8L Integra
1986-89 2.5L Legend
1992-94 2.5L Vigor
1986-89 2.7L Legend
1990 2.7L Legend
1991-95 3.0L NSX
1991-95 3.2L Legend

AUDI
1970-93 All Except 1970-77
1.9L & 1970-73 1.8L

BMW
1987-95 2.5L 325I 525I
1994-95 4.0L 740I

CHRYSLER
1993-95 1.5L Colt
1987-88 1.5L Colt
1992-95 1.5L Eagle Summit
1987-88 1.6L Colt
1989-92 1.6L Eagle Summit
1994-98 2.0L Neon Stratus
1990-95 2.0L Eagle Talon

DAIHATSU
1988-92 1.0L Charade
1988-92 1.3L Charade
1990-92 1.6L Rocky

FIAT
1974-79 1.3L 128 Series
1979-82 1.5L Stranda
1974-78 1.6L 124 Series
1974-78 1.8L 124 Series
1974-78 1.8L 131 Series, Brava
1979-82 2.0L Brava, Spider

FORD
1981-85 1.6L Escort, EXP
1981-83 1.6L LN7, Lynx
1984-85 2.0L Escort, Tempo
1993-95 2.0L Probe
1986-88 2.0L Ranger
1984-87 2.0L Lynx, Topaz Diesel
1985 2.2L Ranger
1989-92 2.2L Probe
1986-88 2.3L Ranger
1986-87 2.3L Diesel Ranger
1991-98 4.6L Crown Victoria

GM
1986-95 1.0L Geo Metro
1989-91 1.0L Firefly (CANADA)
1985-88 1.5L Sunburst (CANADA)
1985-89 1.5L Spectrum
1990-93 1.6L Prizm, Storm
1981-84 1.8L Diesel (CANADA)
1982-86 1.8L Buick Skyhawk
1990-98 1.9L Saturn
1987-88 2.0L Buick Skyhawk
1988-95 2.3L Quad Four
1985-87 3.0L Buick
1979-95 3.8L Buick
HONDA
1986-87 1.0L Prelude
1973-78 1.2L All
1973-78 1.3L All
1980-84 1.3L All
1973-78 1.5L All
1985-89 1.5L Civic
1988-95 1.5L Civic, CRX
1993-95 1.5L Civic Del Sol
1979-84 1.5L All
1985-87 1.5L CRX
1993-95 1.6L Civic Del Sol
1973-78 1.6L All
1980-82 1.6L All
1988-95 1.6L Civic, CRX
1984-87 1.8L Prelude, Accord
1979-83 1.8L All
1986-91 2.0L Prelude
1990-91 2.1L Prelude
1990-95 2.2L Prelude, Accord
1992-95 2.2L Prelude
1995 2.7L Accord

HYUNDAI
1984-95 1.5L Excel Scoupe
1995-98 1.5L Accent
1992-95 1.6L Elantra
1993-95 1.8L Elantra
1992-95 2.0L Sonata
1989-91 2.4L Sonata
1990-95 3.0L Sonata

INFINITI
1990-92 3.0L M30

ISUZU
1987-89 1.5L I-Mark
1990-93 1.6L Stylus Impulse
1987-89 2.0L Impulse
1981-87 2.2L Diesel Truck
1986-95 2.3L Truck Trooper
1988-95 2.6L Truck Rodeo Amigo
1991-96 3.2L Trooper Rodeo Amigo

KIA
1995 2.0L Sportage

MAZDA
1984-85 2.0L 626
1988-92 2.2L 626 MX6
1989-93 2.2L Pickup
1988-95 3.0L 929 MPV

MITSUBISHI
1985-95 1.5L Mirage Precise
1990-92 1.6L Mirage
1989-95 2.0L Galant Eclipse
1983-86 2.3L Diesel Pickup
1994-95 2.4L Galant

NISSAN
1982 1.5L Centra
1983-88 1.6L Sentra Pulsar
1987-89 1.8L Pulsar
1982-89 2.0L Stanza 300ZX
1984-95 3.0L Maxima 300ZX Pathfinder

PORSCHE
1976-83 2.0L 924
1976-89 2.5L 944 Series
1989 2.7L 944 Series
1989-91 3.0L 944 Series
1976-83 4.5L 928
1984 4.7L 928
1985-91 5.0L 928
1992-95 5.4L 928

SUZUKI
1985-94 1.3L Samurai Sidekick
1989-94 1.3L Swift

TOYOTA
1986-95 1.5L Tercel
1981-83 2.2L Pickup
1984-87 2.4L Pickup
1982-88 2.8L Celica Cressida
1987-94 3.0L 4-Runner

VOLKSWAGEN
1976-91 All Except 1.9 2.1L Engine
1990-92 1.6L Golf (CANADA) Jetta
1990-95 2.0L GTI Jetta GLI Passat

VOLVO
1991 2.3L Coupe 940
1986-94 2.3L 240 740 940

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Thank you for visiting the ECONOMECHANIX WEB SITE. Please feel free to comment. We also serve the surrounding communities of Alachua, High Springs, Hawthorne, and Newberry! Gainesville has been my home since 1974, and I've loved Gvl and the Gators since I came here in the fall of 1974 to attend the University of Florida. I loved it so much I stayed and opened my car repair business. Originally it was out of the back of a 1963 Chevrolet wagon, but in 1977 a fellow mechanic and I opened an auto repair shop with actual walls, etc. I stayed in the same location for 26 years, and recently moved my operation to property I bought 15 miles east of Gainesville. I am doing most all the repairs myself now, having reduced my overhead from $1500 per month to practically nothing. I do work by appointment only. I mostly work only on my established customers cars, but I will occasionally take on new clients. E-mail me and I will either make arrangements to look at your car, or I will recommend you to someone who will.