Oil weight/valve noise?

[MustangGT]

I've got a older 4 cylinder (mitsu) that has 159,000 miles, I've tried both 10W-30 and 10W-40, the valves make some noise at start up and then quiet down after driving, is there a particular weight that might help? I'ved tried both the 40W seems to cause more noise to me. The manual says I can use 10W-30,40 and 20W-50.

 

[Justin]

quote:

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Originally posted by MustangGT:
I've got a older 4 cylinder (mitsu) that has 159,000 miles, I've tried both 10W-30 and 10W-40, the valves make some noise at start up and then quiet down after driving, is there a particular weight that might help? I'ved tried both the 40W seems to cause more noise to me. The manual says I can use 10W-30,40 and 20W-50.

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This might not apply, but have you changed you oil filter (to a different type or brand...not just new filter).

Recently, I changed the oil and went with a Purolator PureOne oil filter. Noticed I was getting alot of valve noise at cold startup (actually valve lifters I believe) until it warmed up. Also, starting was louder and harder.

Switched to a "regular" Purolator filter and the problems went away.

 

[Steve S]

Has the valve lash been adjusted lately ? Just guessing.

 

[7TFord]

....At 159K she's probably getting a little tired! There may not be much you can do. The heavier oil would not pump as fast at startup presumably causing your valve noise, especially if it is cooler in the A.M. There may be a chance that you have a dirty lifter. I've read that you can run one quart of ATF and the rest motor oil and drive it for a while, and this will help free up a sticky lifter. You're probably better using the lighter weight oil also.

"Justin"....Apparently the "PureOne" filters have quite a tightly packed filter media inside which may cause some oil flow problems causing what you experienced.

 

[sprintman]

An Auto-Rx clean could do wonders for your high mileage engine IMO. Sure did my 89 Mazda 626 GT 'the goods'

 

[MustangGT]

I've tried numerous different filters with no difference, Maybe I'll try a 10W-30 oil next time.

 

[diesel_fan]

The following may help if your Mitsubishi's 4cyl has HLA's / hydraulic lifters.
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Would the noise be better described as lifter ticking? Does your engine have HLA's vs a solid tappet. Mitsu's with HLA (esp early 90's) are somewhat notorious for making some lifter noise at startup before they are fully pumped up. The older lifters have an extremely small orifice within the lifter body that tends to get clogged with dirt and deposits, which means that air gets trapped inside.

I might suggest that you try Auto-RX or another cleaning products of your choice. FWIW, I have a brand new '02 Mitsubishi with a 4cyl (4G94), and it also ticks away for about 20 to 30 seconds before quieting down.

From information recv'd on another forum I belong to, the Mitsu's HLAs seem to be overly sensitive to oil that is thin or dirty. The 40W may not have helped the problem if the lifter(s) are already dirty or clogged. A relatively thick oil when warm may have a problem flowing through the partially clogged orifice inside the lifter body.

If you can confirm your Mitsu does use HLA's, there is also an air purging procedure in the factory shop manual which helps to bleed out air from the lifters to eliminate any excess noise. This can be a helpful troubleshooting aid.

DF

[ March 10, 2003, 09:56 PM: Message edited by: diesel_fan ]