my audi A4 3.0 engine just diagnosed with hole in exhaust cam lobe, hope in top of lifter, damage to intake cam. alerted initially by a ticking sound in engine. this is a huge repair. can i assume it is unsafe to drive until repaired?
Some motors have hollow camshafts and I recall one, a Brazilian engine made for Pontiac that had an oil hole in each cam lobe. Possibly your Audi is similar and if so, you need to get another assessment of your engine problem. I am wondering if all that you need is a new valve lifter. Light valve lifter ticking in my experience with hydraulic valve lifters, is harmless. Heavy ticking can damage a cam lobe.
Yes, assuming the diagnosis is correct, it’s unsafe to drive. If you continue to drive the car under these circumstances you will do even more damage.
I have to ask, however, what is the mileage on your A4, and how, exactly, did whoever told you there’s a hole in the exhaust cam lobe come to that conclusion?
In order to determine whether or not there’s a “hole in the exhaust cam lobe,” they’d have had to disassemble part of your car’s engine. Did “they” do that?
Since your post indicates you’re still driving the car, I have to wonder how “they” came to this conclusion.
Can you elaborate?
My BS detector is ringing. Loudly.
I’d also hate to venture a guess on this one because there are a lot of unknowns.
It’s possible to have a damaged cam lobe and lifter and this can be caused by lack of regular oil changes, allowing an engine to run with a chronic valve lash problem, etc.
What I’d want to know is who diagnosed this, did they actually tear into it, has it been reassembled, and if any of that is applicable what did they say about it.
If it’s true and has not been repaired then it’s time to park it until it is fixed.
This SOUNDS like lubrication failure, either lack of regular oil changes OR an example of the problems caused by removing the extreme pressure additives from the latest “updated” motor oils to protect catalytic converters…Could also be caused by a defective cam or lifter right from the factory…How many miles on this car??
If you drive it this way, you risk destroying the entire engine.
The car has 99K. I have taken it to 3 shops, 2 of which disassembled the engine and came up with the same diagnosis. The car has had very regular oil/filter changes and I use a synthetic oil. Specific diagnosis includes: 1 exhaust cam lobe severely damaged, hole in the top of the lifter and damage on the intake cam.
I’m just wondering if there is other hidden damage waiting to manifest itself should you spend a lot of money to repair the obvious problems…Engines don’t wear out one piece at a time…I would check around (including online) for a used (salvage) engine and weigh that against repairing your engine…
What caused the failure? At this point, I don’t think there is any way to tell. Defective or poor quality parts or lubrication failure, take your pick…
Until repaired it needs to be parked.
I believe this model uses hydraulic cam followers so this means the problem could have been due to either a faulty follower (odds against that) or a follower going bad due to oil sludging, etc.
In a very rare instance it’s possible the metal could have a fault in it from not being treated correctly during the manufacturing process. Odds are against that also.
I don’t know what your oil change schedule is but depending on driving habits and environmental conditions it’s possible an oil change could be needed every 3k miles or so; synthetic oil or not.
There’s a number of reasons why synthetic oil can sludge up; high humidity and dusty conditions, faulty PCV valves, etc, mostly short hop trips, etc.
Once the lifter starts getting a bit weak (sometimes noticeable by a barely audible tick sound) this means the cam lobe(s) and follower starts on a downhill slide.
The repair costs on something like this would be very large and if it were me I’d try to locate some good used parts. This may take a bit of footwork (salvage yards, eBay, or whatnot, but there is no way I would consider brand new factory OEM parts from Audi. The heart can only take so much.
Maybe what we think is a “hole” is not what the mechanic is refering to. In any case the hardened outer surface of the cam has been breached and its time is limited.
I have seen Chevrolet small blocks that have had the lobes almost ground round,we called them McDonalds cams,engines sounded like boat motors.
I would say its safe to drive it in the shop instead of pushing it.
It does sound odd you had a shop disassemble it and put it back together then another shop takes a look. Much not be to much work to get a look at.
In most cars with overhead cams, its not a huge repair as some engine repairs go, but since this is a
German car, its going to cost like a huge repair. Fortunately, these parts should not damage anything else in the engine. New cam. lifters and rockers and you are good to go.