Did I Just Get Burned?

Gambled on a used engine for the Daewoo swap. It drives fine, no smoke, doesn't use oil in the 80 miles I've driven it so far, way more power.

But, at really light load above 2800 rpm it makes a noise that sounds to me like piston slap. Imagine hitting a chunk of aluminum lightly with a steel hammer. It's not loud, but I can hear it. I don't hear it under load, I don't hear it when using engine breaking, it's just super, super light load.

Am I in the market for another engine?

ur spending money on a Daewoo?

He's in South Korea. Slim pickn's.

NINJAEDIT: By the way, if you're unfamiliar with the Daewoo of Death, here's the build thread for it:

http://grassrootsmotorsports.com/forum/grm/complete-build-thread-daewoo-nubira/25810/page1/

It's an awesome project

Think of it as an Opel.

And the engines are about 300/400 bucks.

Hmm... No experience with Daewoo... But I did have a Sentra 1.6 that had a noise that sounded a bit like what you are saying... At cruising speed (about 50mph or so) if I gently accelerated or just barely maintained speed I heard a noise that almost sounded like pre-ignition... Talked to some people that knew Sentras and was told that the top of the rod bearings had been pounded out when the engine sucked water from a head gasket... Sure enough, when I dropped the pan and looked the top of the rod bearings were ruined at the very top... Installed new bearing and was good to go... I am not saying that is what you have.... But it may be something to consider... How hard is it to drop the pan & look?

Piston slap should dissipate as the motor warms up.....Yes??

In reply to emodspitfire:

Yes it should... I own a Neon, I should know.

I want plates that say PSTNSLP

I don't think I have ever put a used engine in anything without at least looking at the bearing shells while it's out and the pan is easy to pull.

Doesn't go away with heat. I didn't pull mains, in hindsight that was pretty dumb.

Either way, you're commited now. Drive it 'til it pukes. Might be next week, might be next leap year.

Sure its not detonation? Maybe due to a lean spot in the fueling thanks to the bigger displacement?

A loose piston pin can also cause something similar. If it's a light load thing you can probably duplicate it with the transmission in neutral. Also, if that's the same DOHC Holden motor that was used in the Isuzu Amigos there was something about a temperature sensitive timing belt tensioner. No that's not a fumblefinger, there was a temperature sensitive sticker that went on the engine and you had to set the tension in the correct range for a given temp.

See the little notch at approx 7 o'clock? That's the mark on the tensioner, the sticker went on the engine.

DaewooOfDeath wrote: Doesn't go away with heat. I didn't pull mains, in hindsight that was pretty dumb.

Not the mains, the rod bearings. I've experienced the same thing on a couple different cars. Drop the pan and take a look at the rod bearings.

Curmudgeon wrote: A loose piston pin can also cause something similar. If it's a light load thing you can probably duplicate it with the transmission in neutral. Also, if that's the same DOHC Holden motor that was used in the Isuzu Amigos there was something about a temperature sensitive timing belt tensioner. No that's not a fumblefinger, there was a temperature sensitive sticker that went on the engine and you had to set the tension in the correct range for a given temp. See the little notch at approx 7 o'clock? That's the mark on the tensioner, the sticker went on the engine.

I think the Lanos/Nubira 1.6L/1.8L/2.0L was a D series and the Leganza/Rodeo was an E series, or something like that. I don't think they share much.

16vCorey wrote:

DaewooOfDeath wrote: Doesn't go away with heat. I didn't pull mains, in hindsight that was pretty dumb.

Not the mains, the rod bearings. I've experienced the same thing on a couple different cars. Drop the pan and take a look at the rod bearings.

+1

I've experienced similar problems that turned out to be the wrist pin. (small end of connecting rod). The engine ran a suprisingly long time while simultaneously making me insane.

It's much worse, actually. Drove the car from Daejeon to Daegu today (about 100 miles) and discovered:

A) This thing has definitely pushed a head gasket.

B) There's a bearing going south somewhere. The ticking is getting louder and the oil pressure is getting lower.

C) Oil leaks from the valve cover front and back, from somewhere up against the transmission and from like six places on the oil pan.

I think the previous owner massively overheated it, warped every surface in the engine and then drove it around with the busted head gasket until water in the oil destroyed the bearings. Since I can get another one for 400 bucks I can't see the sense in a complete teardown and rebuild.

On a related note I stopped trying to preserve the engine late this afternoon. It'll now burn the tires all the way through first gear from a roll. Seems to run out of steam at about 5500 rpm though.

On another related note, I've officially given up trying to have the car ready to dyno for next week. I was going to do before and after tests for the custom intake manifolds my students are building, but there's no point if the car is blowing half its power out through the radiator cap. Guess we'll just build the parts and test them whenever I get a new engine. Since the time pressures are gone, I might hold out for the harder to find, identically priced 2.2L D-Tech.

On the final related note, I'm definitely pulling the pan on whatever goes in next. Me and my buddy the mechanic are going to do a very thorough inspection. The company I bought this engine from charged me extra to get a "grade A used engine," but if this piece of E36 M3 is grade A I had better learn my lesson about getting impatient and trusting people too easily.

16vCorey wrote:

Curmudgeon wrote: A loose piston pin can also cause something similar. If it's a light load thing you can probably duplicate it with the transmission in neutral. Also, if that's the same DOHC Holden motor that was used in the Isuzu Amigos there was something about a temperature sensitive timing belt tensioner. No that's not a fumblefinger, there was a temperature sensitive sticker that went on the engine and you had to set the tension in the correct range for a given temp. See the little notch at approx 7 o'clock? That's the mark on the tensioner, the sticker went on the engine.

I think the Lanos/Nubira 1.6L/1.8L/2.0L was a D series and the Leganza/Rodeo was an E series, or something like that. I don't think they share much.

The engine I'm dealing with is a D-Tech. In the US market they ranged from 1.6 to 2.2 liters. Probably the two most common applications were the Chevy Aveo and the Suzuki Forenza.

Do you have to give up an engine as a core when you buy another? If not, keep it and rip it apart and rebuild it if it looks possible, both $$ wise and mechanical-wise. That way you're all set when the new used engine goes.

I'm probably going to have to give it back as a core. I'm halfway tempted to keep the original 1.5L and build it for boost though.

Well, good luck.