Terrible engine noise

[StewyN]

Ran into a big one today, My 720 with the z24, started a tiny tick, clatter,rattle kinda noise coming from the engine area, this morning, as the drive went on (appox. 20 miles total) the noise grew louder. it only happened in gear and around 1500-2200 rpm, but was running fine. got close to work and shifted gears and the noise was 10 fold louder and it started idling rough. messed with it a bit and thought i had it running better but about halfway home the noise now was heard at any rpm, in gear or not. it seemed to come and go as i drove, almost like a sticky valve freeing and sticking over and over again. but never going completely away. it finally got bad enough i pulled over and called a tow truck.

 

I'm going to pull the valve cover off and inspect tomorrow but wouldn't mind hearing any other ideas or solutions.

 

this is my second engine in this truck and the last one failed in a very similar way. fine one day and the next... toast.

 

Last oil change? spark plugs, ect? you wanna ask me my religion? MAINTENANCE. i do all the usual tune up stuff on average a little earlier than due

 

Thanks in advance

Edited December 8, 2020 by StewyN

[datzenmike]

Oil level is way more important the when last changed. Check the oil level. Never drive with diagnosed noises. To ignore them is the same as turning the radio up so you can''t hear them.

 

The usual cause for this is the head gasket failing.  How many miles on this second engine???? Near 100K?

[StewyN]

oil level is full, it doesn't leak a drip or burn much if any.

 

i didn't want to drive on the noise, but it wasn't a concerning noise, almost a heat shield or exhaust rattle, until about 2 miles to work. i thought maybe it could be detonation noise afterwards, so i fiddled with the timing just a hair until i thought it was running decent, then i hopped on the road home and it was apparent i had something major going on so pulled over and called the tow truck.

 

millage? unknown. the speed-o stripped out of the trans before i ever owned it. that's all that's wrong with the trans so i never fixed it (gps speed-0 works just fine)

Supposedly the 2nd engine had 80,000ish miles on it when i got it, bought it pulled, and the guy said his dad rolled the truck so they took what was good and scraped the rest, dont think thats the issue either, ive been running it for just over 10 years now.

 

no, have not changed the gasket ever and dont know if the previous owner ever did

 

I get the rough idle, but that would cause lifter noise as well?

[datzenmike]

Z24s tend to blow head gaskets every 100K. Often into the cooling system resulting in constant coolant losses and/or a very steamy exhaust that smells of anti freeze. Other times between cylinders causing poor idle and rough running.

 

Valve train noise? A dropped valve seat but unlikely unless very badly over heated. The valve lash becomes excessive and a lash pad pops out? Broken valve spring? I guess pop the cover off and look.

[Christoffer]

I have an 84 too and this just happened to me. Going up hill and it started making the noise and lost power. It only made the click noise when in gear and at the rpm that you mentioned. Took it to advance auto to see what they thought and it seems that it may be one of the cylinders isn’t firing. What have you been able to find out? 

[datzenmike]

You probably blew the head gasket. Probably between cylinders and this causes the power loss.

[Christoffer]

33 minutes ago, datzenmike said:

You probably blew the head gasket. Probably between cylinders and this causes the power loss.

Oh shit. That could definitely be the problem. Is there a way to make sure that’s the case? Like looking under the oil cap for condensation? This thing has 68000 miles on it so I figure it probably hasn’t had a lot of major maintenance issues. 

[bilzbobaggins]

19 minutes ago, Christoffer said:

Oh shit. That could definitely be the problem. Is there a way to make sure that’s the case? Like looking under the oil cap for condensation? This thing has 68000 miles on it so I figure it probably hasn’t had a lot of major maintenance issues. 

 

Can remove one side of the plugs and run a compression test.

[Christoffer]

1 hour ago, datzenmike said:

You probably blew the head gasket. Probably between cylinders and this causes the power loss.

If this is the case where would you go to buy the best parts? I may just take it to a shop here in Gainesville. 

[Christoffer]

1 minute ago, bilzbobaggins said:

 

Can remove one side of the plugs and run a compression test.

I don’t have the tools for this but will see if I can get a shop to check. 

[Lockleaf]

Compression tester can be rented at most auto parts stores.  You will spend significantly more money having a shop work on this than you will on the basic tools necessary to test and replace the head gasket.

[datzenmike]

You can do this yourself for about $30 but a shop will bend you over for $5-$600. They'll find endless things that need replacing unless family friend.

 

If blown between cylinders two adjacent cylinders may show lower readings than the other two. May..... if the blow out is big enough. 

Condensation in the oil may happen if the blow out is into the water jacket. The steam is pushed past the rings. This will present with mysterious coolant loss.

 

Want to try a Hail Mary??????

When the engine is dead cold from over night. Take the valve cover off and re-torque the head bolts. Borrow a torque wrench and 10mm??? socket. Loosen just one bolt and tighten to 60 ft lbs. When tight move to the next bolt. Do in any order but only one loose at a time