The engine is a 3.1. The engine began running poorly and rattling. It was taken to a mechanic shop. They changed the oil, said there was metal in the oil and it had a rod knocking. This is my neighbors car. He drove it home from the shop. He said it ran ok but less power and knocking. Oil pressure was good. The next morning I ask him to crank it I wanted to hear it. The engine hit a few time never cranking and began to pop thru the intake. The noise I heard sounded more like a loose timing chain slapping the cover. We took the front valve cover off and spun engine. The rocker arms moved. We removed the timing chain cover and it was fine. We removed the plugs and turned the engine by hand to see if we could feel anything unusual. It turned fine but I noticed only the left three valves on both sides were moving. The cam was broken in half. My thinking is the cam cracked and caused the right valves to be slightly out of time, causing noise and lack of power. When we tried to crank it it began to turn loose and when we turned it by hand it came completely apart. We turned it in both directions allowing it to come completely apart. I've been told you can't rebuild an engine with a broke cam because of to much damage to the block. I've been told the block is defective and cant be used. Is this true or is it very expensive but can be done. I can do the work myself. I have all the tools and I've built many engines with good results. I am curious because one of the mechanics is wanting to buy the car for $1000. With a good engine it may be worth $1800. This tells me he has a good engine in his pocket or he can repair it cheaply. Any advice will be appreciated.
Did anyone mention the time, effort, and cost of the valve job that might be necessary? If I understood correctly, the valves were not moving on cylinders 4 and 5. When the #4 and #5 pistons reached the top of the stroke and valves were not closed on cylinders 4 and 5, the valves may have been bent.
If you are still considering repairing the engine, the first thing to do is have your head checked. Then check the heads on the engine to confirm that the valves do not leak. You can do that with the heads on or off of the engine.
QUICK AND DIRTY METHOD WITH HEADS INSTALLED:
Remove rocker arms from the suspect cylinders. Remove the spark plugs. Fill the cylinders with pressurized air and listen for leaks.
http://www.allpar.com/fix/leakdown-test.html
WITH HEADS REMOVED:
Take the cylinder heads off. With plugs in the spark plug holes, invert the heads and set them somewhere where they can sit for a while undisturbed. Fill the combustion chambers with liquid. Water is ok. This isn't rocket science. When it is determined that the valves do not seal completely, find someone who will give you anything for the car.
Unless you have extra money and an emotional attachment to the thing, don't throw any more money in that old thing.
TAKE THE MONEY AND MOVE ON.
P.S. - REALLY DAVE?
Let the car rest in peace.
Kyle: Really??? - YouTube
If you had coolant enter the oil system from the intake gasket failure, it is possible that the cam bearings were damaged leading to a broken camshaft. Depending on where the cam broke, would determine how many cylinders you have that still run. If you lost oil pressure when the failure occurred, that reinforces the broken cam idea, since the oil pump is driven from the aft end of the cam. The 3100's were known for intake failures and resulting broken cams seemed more common than the problems. Certainly, I would not rule out a chain. I might consider removing the forward valve cover and observing the operation of all the valves, especially the aft valves.
If the cam is broken, the engine needs to come out of the car and repairs would likely exceed the value of the car.
Now if you're going to attempt to do this yourself as you have said you have experience, then please follow exactly what iam saying here and it will be very successful. plus please read my notes on this issue here (hope this helps.
~Dave
The engine itself was based on the earlier 2.8L V6 that was first produced back in 1980. The 3.1L was eventually replaced with various versions of the 3.4L V6. Today, the 3.1L still lives on in China where it is being made in various displacements (2.5L, 3.1L and 3.4L) for GM's Chinese-built Buicks. The larger 3.4L version has been imported into the U.S. since 2005 to power the Chevy Equinox.
Over the years, GM has saved a bundle on manufacturing the 3.1L engine by using the production line tooling it originally developed for the 2.8L V6. By simply changing the bore diameter, the displacement of the same engine block could now be increased for more power and torque.
The narrow 60° angle of the V6 cylinder banks was chosen so the engine would more easily fit into front-wheel drive cars and minivans as you probably know seeing you have auto experience! anyway, (though it has also been used in rear-wheel drive applications, too).
Most of these vehicles have aged to the point where they don't have much resale or trade-in value.(myself the Lumina was the best vehicle chev ever built) to this very day i have not 1 but 2 sitting in my driveway) and yes any, or all parts are still for sale as of November 15/2014 not trying to be a salesmen here but if anybody ever needs parts, let me know my email address is [email protected] don't be afraid to use it if this allowed here, after all this is a guys place, and we need to help out other brothers in the automotive field period, i have a 1997 and a 98 and just to many new parts to say on here but each, can can start up like new to this day also.(keep this in mind)
A real low-mileage mint condition car might fetch a couple thousand dollars on a used car lot.
But, many of these vehicles are so old that they are probably worth less than $1,000 - which makes it tough to justify spending a lot of money on repairs if major engine work is needed. Even so, many people are hanging onto their old cars longer than ever these days and are still putting money into repairs to keep them running. now back to the topic at hand here.
Except for the notorious leaky intake manifold gasket problem that has plagued many of these engines, the 3.1L V6 has had a reputation for being a long-lived reliable engine. Consequently, there are still a lot of these engines on the road and people are still spending money keeping them running.
Engine Notes
With one notable exception, all of the 60° V6 engines in GM's 2.7/3.1/3.4L family have been conventional pushrod designs with two valves per cylinder. The one exception was the dual overhead cam (DOHC) "LQ1" version of the 3.4L engine produced from 1991 to 1997.
The 3.1L V6 utilizes a 3.50" bore with a 3.312" stroke crankshaft. The block has gone through half a dozen variants since its inception, with different mountings, sensor fittings and reinforcements for both FWD and RWD applications.
Some of the engines (notably 1990-'95 FWD minivans) had cast iron heads, while most of the later engines came with aluminum heads. The Gen III version of the engine (L82 built from 1993 to 1999, and the later LG8 VIN code J engines) added a composite roller cam and used a number of slightly different cylinder heads. Roller rockers were also used on most 1995-'99 3.1L engines.
If you're swapping in a used engine,interchangeability will depend on the make and model year. The major differences to watch out for would be the A/C compressor and starter mounting bolt holes, and sensor mountings.
The 1988-'92 engines did not use a cam position sensor, some of the 1993-'94 engines had cam sensors and some did not, while all of the 1995 and later engines had cam sensors.
Early versions of the RWD engine and FWD minivans used a distributor ignition system while all of the FWD car applications had waste-spark distributorless ignition systems.
The only "problem" block in the 3.1L V6 engine family to watch out for was the one used in some 1988-'90 FWD cars and minivans, casting #10065459. This particular casting tended to develop cracks near the center cylinders.
PART 2 TO FOLLOW AS YOUR ONLY ALLOWED 10,000 CHARACTERS WILL POST A.S.A.P.
If there is anything else you need to know get in touch with me
this vehicle yes is worth fixing hands down
Chevys never die they just go faster is the slogan lol.
PART 2 ON THIS REPAIR PLEASE A MUST TO FOLLOW IF THIS IS DONE RIGHT!
3.1L, 3.4L (VIN E) and 3.8L Engines The engine must be removed from the vehicle to service the camshaft. With the engine out of the vehicle, secure the engine in a suitable workstand. Remove the rocker cover, the rocker arms, the pushrods and intake manifolds using the procedures found in this section The roller lifters use guide plates to keep the lifters from rotating off of the cam lobes. Remove the lifter guide bolts and remove the lifter guide. The lifters can be pulled from their bores. All lifters must be removed before the camshaft can be pulled out. WARNING Any valve train parts that have been removed with the intention of reinstallation must be marks so that they can be returned to their original locations. Remove the oil pump drive. This is a stub shaft located in the back of engine in the location where the distributor resided in older versions of this engine. It is driven by a gear on the camshaft and is necessary to drive the oil pump. Like a distributor, it is retained by a hold-down clamp. Remove the clamp and lift the oil pump drive straight up and out of the engine. Remove the crankshaft balancer and the engine timing chain front cover, following procedures found in this section. Remove the timing chain and camshaft sprocket, following procedures found in this section. WARNING All of the camshaft bearing journals are the same diameter so care must be used when removing the camshaft so the sharp edges of the cam lobes do not gouge the soft metal of the camshaft bearings. Remove the two screws that hold the camshaft thrust plate to the block and remove the thrust plate. Insert a large screwdriver in the camshaft to act as a handle and to help support the camshaft as it is withdrawn from the block. Pull the camshaft out slowly, rotating the camshaft to help it clear the bearings. Normally, if an engine requires a new camshaft, it likely also needs a complete overhaul. In actual practice, the engine block is stripped of components and sent to an automotive machine shop where the block can have the cylinders refinished or overbored and other checks can be made. Most shops will "hot-tank" the block in a caustic solvent for thorough cleaning. The solution in a hot tank destroys the soft metal in camshaft bearings. In nearly every case, as part of their engine block prepping service, the automotive machine shop will install new replacement cam bearings. If, for some reason, you choose to attempt camshaft bearing replacement yourself, the following should be helpful. A special tool called a Camshaft Bearing Remover/Installer is required. This tool normally consists of a bearing driver and a number of different size expanders, or collets to hold the bearings of a wide variety of engines. These tools vary in quality and cost but are all designed to install the bearing straight, parallel to the engine's centerline. This type of tool can often be rented. Use great care if using substitutes since the block can easily be damaged beyond repair with use of improper tools and methods. Note too, that sometimes if a defective lifter wears a just a lobe or two, and not too much metal has circulated in the oil, it may be possible to replace a camshaft and use the original bearings without removal. Typically, camshaft bearings show little wear, especially in contrast to connecting rod bearings or crankshaft main bearings. NOTE Camshaft bearings, once removed, must never be reinstalled. Remove the camshaft rear cover (plug). This is a round plug, similar to a so-called "freeze-plug." The engine flywheel must be removed to access the rear camshaft cover (plug). From a camshaft bearing remover tool kit, select the expander assembly and driving washer. Install the tool into the camshaft bore and drive out the bearings, one by one. To install: Clean all parts well. If the camshaft bearings were removed, examine the bores in the block. Note that there are oil holes which MUST line up with the oil holes in the bearings or the camshaft will quickly fail. Severe engine damage will result if the oil holes are not correctly aligned. If the camshaft bearings were removed, and you attempting to install them, use the following as a guide. A short piece of 3 / 32 inch brass rod with a 90 degree bend in the end, or an appropriate size Allen® wrench can be used to probe the bearing holes to ensure the holes are proper aligned with the holes in the block. Use care not to scratch the bearing surfaces. With the new bearings, select the proper expander and driver washer from the camshaft installation kit. Index the camshaft bearing oil hole so it will line up with the oil hole in the block. Install all of the intermediate camshaft bearings first. Make sure the oil hole in the bearing lines up with the oil hole in the block. Install the #1 camshaft bearing. Make sure the oil hole in the bearing lines up with the oil hole in the block. Install the #4 camshaft bearing. Make sure the oil hole in the bearing lines up with the oil hole in the block. Apply sealer, GM #12345493, or equivalent, to the camshaft cover (rear plug) and install the plug until flush with the engine block. WARNING All camshaft journals are the same diameter so care must be used in removing the camshaft to avoid damage to the bearings. Coat the camshaft bearing journals with engine oil or engine assembly lube. Coat the camshaft lobes with GM lubricant #1052365. Special cam lobe lubricants are also available. The reason a camshaft needs special attention with its lubricant is that it is usually a long time between camshaft installation and initial start-up. This is especially true on front wheel drive vehicles where the engine must be removed and installed. Thin lubricants will drain away. Camshaft lubes or special oils like GM Engine Oil Supplement (EOS) will cling to the camshaft lobes. In addition, camshaft lobes are lubricated by crankshaft and connecting rod throw-off oil. When an engine first starts, it may not run fast enough to supply the oil needed to lubricate the camshaft lobes. A special camshaft lube protects a new camshaft in the first few critical minutes at start-up and break-in. Do not neglect to properly lubricate the camshaft or it could be ruined in minutes. Start the camshaft into the bore. Often, with all the lube on it, it can be too slippery to handle conveniently. Some technicians will temporarily install the cam drive sprocket to give them something to grip. Turn the camshaft as you install it and use care to keep the camshaft lobes from gouging the soft metal of the bearings. Install the thrust plate and torque the screws to 89 inch lbs. (10 Nm). Lubricate the driven gear of the oil pump driven gear assembly with GM lubricant #1052365. Coat the rest of the assembly with clean engine oil. Install the oil pump drive and tighten the hold-down bolt to 27 ft. lbs. (36 Nm). Install the timing chain and sprockets using the procedures found in this section. Install the remainder of the components in the reverse order of assembly.
If someone offerd $1000 for the car, TAKE THE MONEY!
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It will cost you close or more than 800 to rebuild the engine,if the block is OK to rebuild,and car with nit running engine is not worth that much ,being that old,if he is willing to pay 1000$ ,for,do not wait any second and get the
money as soon as you can,before he change his mind
Yes it can be rebuilt even though it might be better depending on the miles to just replace it . with a top value of $1800 even if u sold it for that the 800 difference wouldnt matter much...what i,m saying is your labor and the parts would definitly come to $800 easy now if who ever owns it plans to keep it a long time then yes fix it. but some times it,s easier and quicker to add 8 hun to the grand and move on GL
Well it depends on what the bearings look like they sit down in a between a valley through the whole cam shaft area my experience is I snapped mine while driving the car!! I destroyed where the cam bearing press into my suggestion to you is take it out inspect it you might be as to get by with over sized bearing but in most cases the block is junk I wouldn't sell the car for a thousand bucks pop a low milage used engine in it for 5 to 600 bucks and keep on trucking that's what I did and mine sits in the driveway still today.
SOURCE: engine want crank
an IC (internal combustion ) engine is dependent on the spark timing for initial start (crank).here since most of it was remanufactured , the spark timing is at fault.
TIME the spark a few degrees before TDC and see the difference .i hope this solves your problem.
SOURCE: 2000 tracker same problem as bonedssss
Just tell him your are experiencing same concern as when you first brought it to him. The new seal may have failed. If you have the time, stay ask to see the results of his recheck. I find most shops are reputable and will admit if they error. parts fail and humans make mistakes. If they work with you then all is good. If not call the credit card company and stop the payment if you truly believe they are not being fair. other remedies are BBB & DMV. Each agency will take a report and do little else. So keep your records, and if they are not fair, take the car to another shop for a second opinion. Keep me posted.
SOURCE: Valve noise
I am from the old school. Start the engine with the valve covers off, back off the rocker nut until the rocker starts tapping then slowly tighten nut until tapping stops then go an 1/8 of a turn tighter. Repeat the same for the rest.I know it will be very messy and you have to watch the oil on the exhaust manifolds for a fire. There will be a lot of smoke. What I do is cut out sheet metal and use it as a shield so the oil does not flow over the head as much.
SOURCE: roller rocker meets valve stem tagging inside of spring
They make valve stem caps to raise the hight of the valve stem & stop the rocker from making contact with the spring retainer.Good luck,
ChevRev
SOURCE: it was backfire'n thru carb i removed valve cover
It is probably still getting oil, but if it is not moving as much as the other exhuast rockers chances are the cam shaft lobe for that valve is wearing away.
Same thing happened to me. As it turns out the EPA mandated that most of the anti-wear (zinc and phosphorus) additives be removed from most motor oils. This is because of emissions and because thier presence can damage the catalytic converter. Diesel oils still have all of the additives. I have been putting at least one quart of shell rotella-T into every vehicle we own. Running pure Rotella-T in the one I just put the cam in for now.
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