2000 Mitsubishi Galant clicking / ticking noise?

From the symptom description, I believe the noise is from the valve lifters. Mitsubishi engines tends to have this problem after some time and the only way to resolve it is to service or replace the lifters. It is only required to service/replace the lifters concerned to rectify.

Cost would depend on how many lifters have to be replaced and the engine you have.

You can use the vehicle without any problem and if you can live with it, just ignore it until it becomes consistent. I believe presently the noise intermittently disappears after warming up and might be on and off.

One of the most common cause of this problem is use of additives and lack of oil change.

There is a possibility the noise would lessen gradually.

When additives are used, they tend to build up sludge which is the primary cause of the lifters malfunctioning. When engine flush or cleaners are introduced, the cleaning process might be incomplete and under such circumstances, noises would appear. You can't really put the blame on them as the noise could appear anytime, even after a normal oil change as the condition of the lifters were already bad when sludge buildup had occurred long ago.

For this engine, when sludge builds up, it is a matter of time before the problem occurs. Those that uses additives regularly would tend o accelerate the process, especially if the oil change interval is prolonged and vehicle is not of very high mileage.

Sorry I am not familiar with Auto-RX so is not able to make any comments on that.

This is not going to damage the engine. Just some performance related irritating noise.

The noise occurs when the lifters leaks internally resulting in them not maintaining their desired height and after the cleaning phase, the noise might still be there. I have dealt with many such cases and seems most of them even if new lifters were replaced, noise would still come back, just a matter of time. I would put it as a design and wear and tear problem.

I am irritated by abnormal noises and if it is my vehicle, I would wait for the cleaning pahase to be over and if noise does not improve, I would remove the lifters to service them first and check for abnormal wear on the lifters.

Being a 4 cyl engine, the job is not too difficult.

With regular oil change and no coolant losses or overheating issues, doubling the mileage is not a problem. The only thing that can occur would be worn valve seals resulting in oil consumption and smoke emission.
The seals can be replaced with appropriate tools, without removing the head and if the job is done, you are good to go beyond 300 k miles.

Engines nowadays are built to last and seldom fail with proper maintenance.

Inspections would not count for anything if maintenance are poor. As regards to transmission, they don't seem as reliable as would be preferred. They are rather fragile and not built for robust usage. If you are not a hard driver, it would last longer.

The first sign of erratic shifting would be an indication something is going wrong. It might fail early but sometimes it can last quite long as well depending on the situation. The correct specification transmission fluid for Mitsubishi is very critical. Incorrect use would cause premature failure.

I believe the orange seals you mentioned are the valve seals because when repairs are carried out on the valve trains, they would have to be replaced. OEM would be metal color instead of others.

I don't recommend using additives as I have seen many engine failures due to them. The sludge buildup due to additives are higher and more dangerous than anything else and can clog oil passages or the oil strainer in oil sump.

The job of good engine oils are to remove sludges from the engine and during regular oil change it is always recommended to drain the oil when engine has just been shut off.

The lesser sludge buildup the cleaner the engine will be and the longer it will last. Shorter oil change intervals would keep the engine clean as the longer oil stays in the engine, the more sludge it is going to collect.

I change my engine oil every 3000 miles with regular grade engine oil and at 100 k miles, you can see the valve trains are as good as new. The drained oil would only look slightly brown.

How do you know the additive is compatible with the oil you are using?
How would you know the additive is dissolving the sludge and not pulling them down in chunks?

When sludge build up, they would stick anywhere in laters which would thicken over time. Any external factor can trigger these to collapse and be drained into the oil sump. If they can be dissolved, it would not clog the oil strainer. If they are sucked up by the strainer in a clump, oil volume to the oil pump would be ruduced resulting in oil pressure loss.

Oil strainers would not get clogged if they are not subjected to accumulation of sludge. The ckicking noise from your engine is not from the clogged strainer. It is the hydraulic lifters which are not getting sufficient or leaking oil pressure. It cannot be fully be attributed to the oil as some could be due to wear over time.

Those who produce additives would tell you the advantages of their product but would they ever tell you the disadvantages? Do you still remember how the tobacco companies were sued for their product?

In theory their product might be good but in practice, it might be another story.

There are poeple who recommends you to use additives and then comes along someone with a product to clean the engine because of sludge buildup. That is life cycle, everybody is out to make something out of nothing.

Sporadic use of additive is ok but continued use is where the problem lies. A one time use of additive would not result in much accumulation of sludge.

These are all my personal thoughts and I have only my experience and word to back me up so they should not be used as an argument.

The saying goes, " A glass of wine is good for health" If you try too many glasses, it is not a good ida.

The strainer is located in the oil pan anf it it is parially clogged, you might not notice it unlesss you have a oil pressure gauge which might drop in pressure at high speed. If it is badly clogged, the oil pressure indicator lamp should turn on or flicker.

To check on the status, the oil pan would have to come off.

The valve lifters are located under the valve cover. Refer to Fig 21 & 21a. Items 14 & 17 are the hydraulic lash adjusters. They are moving components under stress so wear can occur resulting in emission of noise. However if it is due to wear, the noise would be rather consistent and not fade away intermittently.

When there is sufficient oil pressure and lubrication, there would be minimal noise.

Valve lashes are hydraulically operated so are non adjustable.

Replacement time for the valve lifters is 2 hours. They are under the rocker arm and that would have to be removed so they would come off together.

After removal of the lifters, any that cn be compressed without releasing the pressure hae to be serviced or replaced. When replacing, it is best to replace all.

There should be 12 lifters.

How long the engine would last would depend on other factors as well but generally an engine that has been well maintined and does not have overheating issues would almost last forever.