I just purchased a 1989 Toyota 4 runner. It runs great, idles smooth and everything. I noticed that when i crank it up it seems to knock or rattle a little bit in the engine (not sure how to word the sound) but once the engine idles back down the noise stops...it only lasts for a few seconds. I'm not worried but I'm wondering what it could be..valves? Any ideas?

 

Valves sound more like a ticking noise, a knock is more like knocking on a door. Sounds like the valves are a little oil starved at start up. That could be anything from an oil filter leaking down due to defective anti drain back valve in filter or poorly designed valve in filter. Changed oil and filter recently, what did you use?

 

Sounds to me like it makes noise till the oil pressure builds up.
I'd change the oil using good quality oil and a TOYOTA filter. Some filters will let the oil run out of the filter when shut off. When that happens it takes a few seconds for the oil pressue to fill the filter back up. Over time this will wear internal engine parts, bearing etc, cause it to make a rapping noise, lifter noise, when started till the oil pressure builds up.
Won't hurt to do a oil pressure check either with a manuel gauge instead of going by the dash gauge.
Good luck

 

Thanks a lot, I'm changing the oil tomorrow and adding some Lucas; i felt like that would fix it. It's been a long time since an oil change.

 

some filters have terribly designed anti drainback valves that don't seal. frams tend to have that issue. If the engine doesen't have oil at startup the top end will be starved for oil for a few seconds.

I personally haven't been a big fan of the lucas products, but plenty of people are, so it might be worth a try. I've never used it in an engine, just differentials. It does make a mess if you spill it though, so watch out for that.

 

so an oil change should do the trick? If not, where should i go from there? Tonight, I went up a "really" steep hill and noticed the knocking continued a little so i'm sure its the oil.

 

Is there any oil in it?

 

My 95 4Runner has 160k miles and I change the oil every 2-2500 miles or so with castrol GTX 10W30 and it likes it. Changing the oil frequently especially on these old trucks is crucial to longetivity.

 

Keeping the oil full is important. get out there and pull the dipstick!

 

timing chain?

 

I don't like Fram filters either. I usually use Purolator Pure One filters.

Since we are on the subject, I did use a Toyota filter on my truck and my wife's Celica two oil changes ago to see if there was a noticable difference. There was not. In fact, neither one had ANY oil in the filters when I removed them. Not a drop. The car had been sitting all night in the garage and the truck sat for maybe an hour before the oil change. As a result I went back to the Purolator since they are easier for me to obtain.

As far as the noise goes, could it simply be that the aftermarket chain is a bit louder than the Toyota chain? Do you have the steel guide kit? The chain does contact the guides on occasion, thus the reason to replace the plastic with steel. I would tend to believe that one could more easily hear the chain contact the steel guide.

 

I checked the oil first thing and after the 150 mile trip, and it was full. Oil is pitch black; i'm riding down to Gainesville tonight to pick up the toyota oil filter and i got some Castrol GTX 10w-30 today, i've always used that. So, i'll update tomorrow and let ya know how the oil change goes and see if that fixes anything.

 

I have a 1995 4runner 4x4 with a compleat new top end. When I start it up, it sounds like the valves want to tick right out of the valve covers, but it only lasts for about 2 sec. It always did this since I got it. I did buy it used, so I do not no what it did at new. I tried the LUCAS, and ther is no difference at all. I also use a NAPPA GOLD OIL FILTER and still no difference. I really don't think you have to worry about it if it is only at start up. I also went to CASTROL 10W40 and it seemed to help a bit. You might want to try that as well. But for your info, I do use LUCAS at every oil change at 3000 miles.

 

Sounds good to me, thanks a lot. I'll try the 10-40. As for the Lucas, I'll have to miss out on that this time due to a "crunch" of money. Next time, however.

 

its the timing chain, could be streached out. How old is it , could be the tenisinor. What i would do is run truck to normal temp,pull the valve cover and re lash the valves, While in there look at the chain an inspect put cover back on and see if that helps

 

I got the oil change done this morning after giving the plug and the filter a good fight but I won. Knock is still there, though not as often or as bad.
I'm not a very experienced "mechanic" yet, so what does "re lash" the valves mean? How would I check the timing chain and what would I look for?

 

Ive heard brand spank new motors tick or rattle for 2 or 3 seconds at start up.. I'd change oil and not worry about it.. mine does the same thing , always has

 

That works for me, it runs great, just needs a little tlc. Gotta get a tune up done, got an exhaust leak, and theres a few squeaks, rattles, and pops coming from the front end so i gotta check those out sooner or later...but there very few and far imbetween so i'm not to worried.