Extreamly LOUD uper engine noise.

[danieldialtone]

I am looking at an 86 Terrel 4wd and it has a very loud clacking in the back of the head around cyl 4/ fuel pump area. almost a defining clack almost like an old Detroit diesel injector noise. bad valve? bad valve spring? the valves don't seem to be out of adjustment. Its not a piston rod. its definitely from the upper part of the engine.

Thoughts?

[irowiki]

The fuel pump could be noisy too, or the distributor! Use a long screwdriver with the handle held to your ear to try and pinpoint it.

[dlb]

my guesses are piston slap, fuel pump, and a valve needs adjusting. hopefully it's the last one but if it's the first, you might end up needing to rebuild it sooner than later.

i would expect a worst case scenario when working out a price for the car.

[Petros]

it could be those things, or something else.

It is possible something is striking the piston top. I once pulled an engine from the wrecking yard where the piston was striking the head because there was so much wear in the bearing. Amazing they were still driving it with that much slop in the bearing. It must have made a loud "clack, clack, clack" when it ran. the rod was slightly bent, the head beat up, the piston distorted enough to break the rings, crank journal was shot. it was still running, but it was pretty much scrap metal.

[jimcrazy]

could be carbon build up, happened to me once even pulled valve cover off to look for something broke, rev the crap out of it noise gone

[4doorVIP]

mine makes these noise due to it needing new manifold gaskets.. I have the gaskets I just need the time to put them in haha

[drege]

Foreign body in combustion chamber?
Worn/broken valve spring? (do they have springs? - I had a courier/B2000 {don't remember which now} that had an intermittent sticking exhaust valve
If it were crank rod bearings you'd know - the old 'rod knock' emanates from deep in the engine.
I can't imagine the fuel pump, it'd probably not start/run.
And distributor would greatly affect its timing if there was play/slop in the shaft; am I right? I'm just guessing, I'm no knowledgeable distributor guy, OP.

[xirdneh]

the first tercel we got started knocking at around 110,000 miles
to me it sounded like a metallic knock
i was thinking valve or rod
tried the screwdriver to the ear thing and the noise seemed to be coming from the fuel pump area
one day as i was driving by the local toyota dealership i decided to pull in and see if anyone would listen to it
the guy that ran the shop had me pull into the building where they worked on the cars
he listened to it for a second and walked over to the next bay an grabbed the guy working there
the mechanic walked over, listened for about one second and said that's a bad timing belt, then he turned and walked away
i drove home thinking that was ridiculous
so i replaced this and that and checked this and that and messed with it for a while
nothing fixed it so i replaced the timing bet
it was the damn belt
that only happened once out of the couple dozen tercels i have worked on
just saying it can be the weirdest thing sometimes

[drege]

F*CK YEA! I'd say you got lucky finding a dealership mech that could think their way through a sound and good thing cause these are interference engines.

[dlb]

these are interference engines.

they're actually non-interference engines, drege. which is another great thing about them.

[marlinh]

Xirdneh, was there anything obvious with the belt when you removed it to explain the noise?

[xirdneh]

i did not see anything wrong with the belt
it had to be near the end of its lifespan at the time
but that was my first experience with belts so i did not know much back then (around 1990)

[drege]

I coulda sworn I read somewhere in here early on that they were, but ok, great - I've been stressing my timing belt, it's got a little sticker says it was replaced something like 95,xxx miles ago, and it has the little hair line cracks that old rubber gets.
So I feel better I can just have my tools and timing light along with a new belt in the back.

[marlinh]

Gee, Drege, why don't you change your belt if you know it is cracked when it is convenient and not on a road trip when it breaks all of a sudden.

[dlb]

Gee, Drege, why don't you change your belt if you know it is cracked when it is convenient and not on a road trip when it breaks all of a sudden.

haha, well said, marlinh. a timing belt job is also a good time to do the water pump, which might get neglected if you're just trying to get the car running to get home.