Oh boy, valve knock? Video inside

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Neu
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Oh boy, valve knock? Video inside

Post by Neu »

Hey y'all.

I've had a decent knock coming from, I think, cylinder 4 or the valves for cylinder 4.

The knock is somewhat recent. It mostly started after I put the timing back to around 5 degrees TDC, but im' not sure it's related.

So I took a video for everyone to check out. Here it is. Tell me what you think this ridiculous knock most likely is. https://photos.app.goo.gl/gquQ7r14gKaosnp9A

I've also recently gone through like 2 qts of oil within a week or so and it isn't leaking as far as I can tell. This has occasionally happened with this car since I got it. The oil level will be fine for a month and then suddenly it'll drop a decent amount.

I pressure tested all the cylinders, #1 is 130psi while all the others are 150psi. The cylinder 1 spark plug had a pretty good amount of carbon/oxide build up after only about 2 months of driving(1500 miles or so?) The other plugs all seemed pretty good. Cylinder 4's plug did have a lil bit of oil on it but that's not surprising as my valve cover was leaking until i replaced it recently.

Also the fuel pump has been replaced so I don't think it's that. I also re-adjusted the valves maybe 2 weeks ago. They were all pretty good but cylinder 1 was pretty tight. I don't think adjusting the valves did anything.

Any help is appreciated! I dont want to do an engine swap or rebuild this one, lol.
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Re: Oh boy, valve knock? Video inside

Post by Petros »

that does not sound like it is coming from the low end (connecting rod or crank bearings). sounds like a problem with valve train or rocker arms, or somewhere else in the head.

Take off the valve cover and carefully inspect all of the valve springs, guides, rockers and the cam. a broken valve spring can act like this or damage rocker arm. if you do not see anything, use a mechanic's stethoscope, or a long screw driver pressed to your ear and pressed to the various parts, and run the engine with the valve cover off for a short minute or two (it will splash motor oil everywhere, so be ready for it). it might even be a faulty fuel pump arm rattling around.

do not drive it until you know the source. if something breaks loose it could trash the whole engine. right now it may be fixed with just a few replacement parts.

Good luck.
'87 Tercel 4wd SR5 (current engine swap project)
'84 Tercel 4wd (daily driver, with on going mods)
'92 Mazda MPV 4wd (wife's daily driver)
'85 Tercel 4wd DLX auto(daughter's daily driver)
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Neu
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Re: Oh boy, valve knock? Video inside

Post by Neu »

removed
Last edited by Neu on Sun Apr 10, 2022 11:32 am, edited 1 time in total.
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Neu
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Re: Oh boy, valve knock? Video inside

Post by Neu »

some videos https://photos.app.goo.gl/i6MDEa3QRbSsahKN8 with a pic of the fuel pump arm.

Using a screwdriver to listen a bit better it's definitely coming from the back of the engine, cylinder 4 area.

Maybe my fuel pump isn't on the cam properly? I replaced the fuel pump 3 months ago.

This is probably related, but about 2 weeks ago my throttle response changed. For example, if I'm in 2nd gear at about 2300rpms and I put my foot down i get horrible throttle response and it somewhat "lugs" or cuts out until the rpms get above about 3200.
Last edited by Neu on Sun Apr 10, 2022 12:45 pm, edited 1 time in total.
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rer233
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Re: Oh boy, valve knock? Video inside

Post by rer233 »

You could try removing the pump and starting the engine (should run for a while with no pump.)
Good luck!
if it aint there, there's a good chance it won't break!
83 SR5 Silver/Blue (Snowmobile/work beater)-totaled but drivable
85 SR5 Blue
88 SR5 White (the 'good' one)-not anymore-totaled
87 fwd silver wagon a/t
87 4wd dx Cream (a/t- not anymore- now m/t)
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Neu
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Re: Oh boy, valve knock? Video inside

Post by Neu »

Good idea rer233. I'll give that a shot once the rain lets up in a bit.
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Re: Oh boy, valve knock? Video inside

Post by Neu »

Yay! It's the fuel pump. Thanks.

Time for a return.
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Re: Oh boy, valve knock? Video inside

Post by eightyfive4WD »

Neu wrote: Sun Apr 10, 2022 2:06 pm Yay! It's the fuel pump. Thanks.

Time for a return.
Glad it was as simple as replacing the fuel pump! What did you determine was making the fuel pump cause such a racket? Was it just that the fuel pump arm wasn't making proper contact with the cam?
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Neu
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Re: Oh boy, valve knock? Video inside

Post by Neu »

I think it's just a cheap/shoddy fuel pump. It's the $18 one off rock auto. The replacement is gonna be from napa so hopefully it doesn't happen again.

The new one gets here tuesday so I'll check it out once it's replaced and update.
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Re: Oh boy, valve knock? Video inside

Post by Petros »

Good! it was an easy, and relatively inexpensive fix.

don't waste any time with parts made in communist factories in the orient. even if cheap, they are not worth the effort to have to keep replacing them.

unfortunately as these cars get older, there are not a lot of options for getting quality parts.
'87 Tercel 4wd SR5 (current engine swap project)
'84 Tercel 4wd (daily driver, with on going mods)
'92 Mazda MPV 4wd (wife's daily driver)
'85 Tercel 4wd DLX auto(daughter's daily driver)
'01 Honda Civic (other daughter's daily driver)
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Neu
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Re: Oh boy, valve knock? Video inside

Post by Neu »

Welp, it continued.

I swapped out the mechanical fuel pump last week and the knock seemed to have went away.

Well, yesterday I was driving out east through Portland and suddenly the engine changed sounds. I pulled off the interstate to check the oil and it was bone dry. That's pretty odd because I checked it that morning before I left. There was also now a knocking sound, a hard one. So I topped the oil off and the noise somewhat went away. I got back on the interstate and within a mile or two I could tell something was pretty wrong. I got it towed back to my house and the knock is pretty terrible. I've attached a video.

https://photos.app.goo.gl/oSkDp3VRDDMGviv76

I can also see oil smoke coming out from near the fuel pump while the engine runs, like maybe it's escaping from the manifold or burning off somewhere. Not sure on that.

Anyway, I'm now in the market for a new engine or tercel.
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Re: Oh boy, valve knock? Video inside

Post by dlb »

That's funny, I just had a similar experience with my 91 corolla wagon. It had been running fine, zero issues, then one day on the way back from the hardware store it sounded like it might be running just slightly rough, so slightly that I thought I was probably imagining it.

A few hours later, I had to run back to the hardware store and this time the car didn't want to start, took a lot of cranking before it caught. Eventually it did and I got just down the road when it became obvious it was definitely running rough now. I turned around and went home to avoid the possibility of being stranded at the hardware store, and when I checked the oil at home there was nothing on the dipstick -- despite the fact I had checked it just a few days before and it was great.

I added a bunch of oil and then did a compression test, the first two cylinders were about 15 psi while the other two were around 140. I'm not interested in doing head gaskets anymore, and luckily our mechanic lives just down the road so I limped it to his place without issue. He found that it was indeed the head gasket. Runs like a top again.

So my advice is to do a compression test and see what you find there.
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Neu
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Re: Oh boy, valve knock? Video inside

Post by Neu »

I did a compression test not even a week ago. Cylinder 1 - 130psi, cylinders 2-4 were 150psi. There was carbon on cylinders 1 and 4's plugs. Cylinder 1 was quite fouled with carbon while cylinder 4 had oil on the threads. cylinders 2/3 have no fouling or oil on the plugs. I'll do another compression test this evening or tomorrow.

The smoke coming from near the manifolds makes me think it might be a head gasket. I popped the valve cover off real quick and turned the engine over by hand. I didn't see anything out of the ordinary in regards to the cam/rockers/valves.

Another detail, over the last week or so I've had white smoke in the exhaust. Mostly on start up, but there were also poofs of white smoke after shifting up. Another another detail, I've had "lugging" on throttle from 2750 - 3500rpm for a few weeks(it loses RPM/Power if I go 1/2 throttle or higher in that RPM range, but it will "catch up" after a few seconds). I figured it was a carb issue but maybe not.
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Neu
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Re: Oh boy, valve knock? Video inside

Post by Neu »

And the results! These plugs are less then 3 months old. I also cleaned all the area around the plug ports when I ran the engine with the valve cover off a week or so ago, so the area around the plugs should be decently clean.

https://photos.app.goo.gl/ea8VnyJPBkJCspYG9 Each cylinder has 3 images: spark plug, plug port, and compression result. I started on cylinder 1. Looks like cylinder 4's compression has dropped ~35psi over the last couple weeks. Both cylinders 1 and 4 have significant carbon/oil on the plugs, along with oil around the plugs themselves.

Also judging by what I can see through the plug holes, cylinder 1 has a ton of carbon inside of there.

Not looking too hot.
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Re: Oh boy, valve knock? Video inside

Post by rer233 »

First of all, how much oil did you have to add to bring it up to the "full" mark on the dipstick? Have you tried removing the pump again and starting the engine to see if the noise goes away? Oil leak could be coming from between the fuel pump and cylinder head.

Good luck.
if it aint there, there's a good chance it won't break!
83 SR5 Silver/Blue (Snowmobile/work beater)-totaled but drivable
85 SR5 Blue
88 SR5 White (the 'good' one)-not anymore-totaled
87 fwd silver wagon a/t
87 4wd dx Cream (a/t- not anymore- now m/t)
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