Results 201 to 208 of 208
Thread: SupraMoto's '83 Resto
01-10-2017, 02:19 AM #201
I think I discovered what the root cause of the damage to my valve train and the rest of the engine was.....
I was cleaning the head oil pressure regulator and found that the plunger & spring in the control valve was totally plugged up and seized with crud. I carefully worked it loose and cleaned it (sorry I don't have pics from before cleaning).
Normally the oil pressure in the hydraulic valve lash adjusters is regulated down by this regulator. Since this was seized, instead there would've been the full oil pressure from the oil pump being applied to the hydraulic valve lash adjusters, causing them to apply too much force against the rocker arms (followers). This caused wear on the cam lobes and the surface of the rocker arms (pic). As the metal wore down, the metal particulate circulated though the oil system becoming embedded in the main bearings and causing damage there.
[the original rocker arms, showing the wear grooves from being forced too hard against the cam by the lash adjusters).
The oil pump itself has a pressure regulator also, but it would be a higher pressure that the head can handle safely.
Since this oil pressure regulator is so easily accessible on the top of the head, its very advisable to check the free operation of the control valve and clean it out if necessary. This little piece is so critical.
Sponsored Links Remove Advertisements
01-10-2017, 03:09 AM #202
Another good reason to keep clean oil of the correct weight in the engine!1985 5-speed "Ms. Swan"
OH, What A Feeling!
01-10-2017, 04:11 AM #203
I like the new Pennziol full synthetic made from natural gas.
I'll trust that lubricant to clean my engine internals,when I do too many short trips and clog up my EGR,and other important parts.
My right foot dictates the carbon cleaning schedule.
Like a thoroughbred horse,it likes to be exercised.
Just change the oil,depending on your schedule,not the previous owners/drivers schedule.
May your engine/drive train last as long as it can.200,000 Miles is not that difficult or more,easily.
There are more *really* high-mileage 5 M's here,on this forum.
300K is pretty good, and I applaud the owners.
Sponsored Links Remove Advertisements
01-11-2017, 04:23 PM #204
You should see if you can get a replacement for that spring in the regulator from Toyota still. Whenever I reuse an oil pump I at least put a new pressure relief spring in. Springs soften with age and miles, messing with the correct oil pressure. On the oil pump this results in lower peak oil pressures and that spring controls the bleed off. Actually the spring in this regulator works the same way as I recall. If that piston was stuck open, not only would the head (it controls flow to the cam journals too) see higher oil pressure then intended when the oil pump is producing max pressure, but you would see lower oil pressure at all the other times. Further contributing to wear on your lobes and journals.Black 86 mk2 Project Car
New SDR 86 mk2 Daily User, Highway Cruiser AND Parking Lot Abuser in the works!
01-11-2017, 07:58 PM #205
I have tapping noise coming from my rockers, and wondering if this could be the source of my issue, even if it is free (I cleaned it 2 years ago)...?
01-11-2017, 10:12 PM #206
01-11-2017, 10:22 PM #207
01-12-2017, 11:12 PM #208
Try some carburetor cleaner to loosen up the sludge that holds the lifters in.
Just work the lifter around until the carb clean cuts the crud. WAY more nasty chemicals can be used.
I have seen posts where the oil pressure relief spring had been shimmed with a washer or 2.
The hot oil takes the temper out of the spring,besides time.
Users Browsing this Thread
There are currently 3 users browsing this thread. (1 members and 2 guests)