Rattling sound on throttle LD28

[kossak]

I everyone,

I own a Nissan Laurel from 1986 with the LD28 engine, with 225.300 km on board.

The engine was runing fine but for a week now is started to sound strange under throttle, some kind of rattling sound.
On iddle it seems to run&sound OK, but it not smooth when accelerating.
I've checked the oil level and is OK, oil was changed like 2000km earlier.
I suspect that maybe I need a valve cleareance but I don't know.
I'm afraid to drive it in this condition, I'm afraid that I could do some serious damage to the engine.

I recorded a video, I will come back later with a better quality one.
http://www.youtube.com/watch?v=pBWZGEssl4w

If anybody has any kind of ideea what it should be, I would be grateful.

Thank you very much.

[asavage]

I'm not hearing a rattling sound. On the vid, it sounds like a dead cylinder. The is relatively easy to check, with only a couple of wrenches. With the engine running, loosen an injector line nut at the injector (requires two wrenches). When the nut is loosened, fuel will dribble from the injector line and will not go into the injector, and that cylinder will not fire.

After testing, re-tighten the injector line nut. Test one cylinder at a time, with the engine running.

Have a friend hold the accelerator steady so the engine is at a fast idle (faster than normal idle) while you loosen each injector nut. When you loosen a nut, the engine speed should drop, and when you tighten the nut, the engine speed should rise. If you loosen an injector line nut and the engine speed does not drop, you have identified a cylinder that is dead (not firing). Proceed with a compression test, or if you like cheaper work, swap the injector for that cylinder with one from another cylinder.

-----------

A LOUD knocking sound can be a failed injector, one which does not close properly and which dribbles fuel and/or opens prematurely. But I do not hear a loud knocking sound.

-----------

For a really bad sounding LD28, listen to this one:
http://www.youtube.com/watch?v=0ftUishODRM

HTH

[windsock]

For a really bad sounding LD28, listen to this one:
http://www.youtube.com/watch?v=0ftUishODRM

WOW thats a shocker, what was wrong with that engine Al? Is that what a failed injector sounds like?

Phil

[kossak]

Thanks for your answer! I calmed down a bit:)
I just hope is nothing more serious....but your explanation seems the most plausible of all I was thinking of, because this knocking apeared from nowere, from one day to another.
Probably it would be a great idea to change the fuel filter, to prevent this kind of things to happen again, I don't know when it was changed last time because I have the car only for 3 months.

However, I have to drive home the car first( about 200 km) and take my father to have a look at the engine, he's a mechanic

I will come back with the resuts after this.

Luckily I have another Laurel at home, a '84 model with an LD28 engine as well. So if I need anything, there it is:)

Finally I want to say that this forum helped me with a lot of information about this wonderful engine, I was browsing it for some time now.
Congratulations to everyone who made this possible:)

Cheers,
Florin

[asavage]

For a really bad sounding LD28, listen to this one:
http://www.youtube.com/watch?v=0ftUishODRM

WOW thats a shocker, what was wrong with that engine Al? Is that what a failed injector sounds like?

At a guess, from the sound quality we get, it's running on only four of the six. Why? Anyone's guess. Blown head gasket? Melted pistons?