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View Full Version : Engine does not like hypermiling. Valve tappets make noise


Shrek
09-19-2008, 05:05 AM
The engine sometimes make a noise like the valve clearance is wrong. I learned that hydraulic tappets are self-adjusting and discarded this as explanation.

Then the noise was gone all of this summer (after I changed oil), and I don't know if it was the temperatures or the oil that made the difference.

Now the noise it is back again, and I finally think I understand what is happening:

When driving with high load and low RPM (mostly before the engine is hot), the tappets do not get properly filled with oil.

This is only a problem when having 50-80% load and low rpm because the
valves are very hard to open due to cylinder pressure, and they are open for a longer time, allowing the oil to escape the tappets faster than they are filled.

I guess I just have to drive with higher rpm if an oil change does not solve it.

msirach
09-19-2008, 06:59 AM
No, A higher RPM is not the answer. What is your air temps now?
If it started happening after is started getting cold, it could be an oil issue.

What weight of oil do you use?

Is it synthetic?

How many miles has it been since your last oil change?

kendan
09-19-2008, 11:26 AM
I have a few ideas:
1. You have excessive sludge built up in the oil pan and it is working it's way into the oil filter. After you have gone so many miles after changing the oil, it may be getting clogged
2. Oil passages up to the valves are getting restricted also due to sludge. The oil change may be flushing the restriction, temporarily.
3. The oil pump may be pumping at reduced pressure, not enough to trigger a low pressure warning but enough to starve the engine at low rpm.

Just a few ideas off the top of my head...one possible solution may be to change the brand of oil and/or oil filter. A higher quality filter may be less prone to restriction. A different brand oil may perform better.

msirach
09-19-2008, 12:11 PM
I have another idea to go along with kendan's. What BRAND of filter are you using. I have dissected several brands of filters and Fram is TERRIBLE. It looked like it was manufactured out of brown cardboard and paper towels. The filter could be the problem.

Ophbalance
09-19-2008, 12:36 PM
The (mini)Mopar folks have noted this about the stock Fram filters for a long time now. I purchase Motocraft filters myself.

Shrek
09-19-2008, 12:48 PM
I have another idea to go along with kendan's. What BRAND of filter are you using. I have dissected several brands of filters and Fram is TERRIBLE. It looked like it was manufactured out of brown cardboard and paper towels. The filter could be the problem.


It is all original toyota oil (5W-30, i think) and filter, changed in the spring this year, now at maybe 8000 km out of the 15000 recommended maximum.

I've changed about once a year or after 15000 km so far, and that is probably what the engine's been seing before i got it too...

Electrify
09-22-2008, 07:05 AM
Not sure if I can help, but I recently took my used car in for its first oil change/tune up since acquiring it (2001 Echo AT). When I first turned it on, I noticed a slight leaking/hissing sound I had not heard before. It was very slight and did not think much of it.

This morning I had to drive my girlfriend to work, and when I turned it on that slight leaking/hissing sound was MUCH louder. I turned off and on the car, and it was back to a mild sound till I got to a red light when it started again. Re-started the ignition and it was almost gone again. Got on the highway and it was gone for good.

Today it was MUCH colder than most days, so I think I simply needed to have it warm up more. I took it to Midas, so I really don't know what brand of oil it was, other than 5W30 (I think).

msirach
09-22-2008, 07:26 AM
I think I would change the oil again and have it inspected. I change my own so I KNOW what condition everything is in. I hope its nothing like the catastrophic failure at this thread (http://www.cleanmpg.com/forums/showthread.php?t=15999) . If it is the lifters for sure, the oil pressure needs to be checked. Pressure should never get so low. What is the temperature there now compared to your warm season? They may have put too heavy weight of an oil in it.

Shrek
09-25-2008, 07:33 AM
It seems to have gotten a bit better after changing oil and grillblock.



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