Sign in to follow this  
Followers 0
siteations

Loud (really Loud) Engine Noise

13 posts in this topic

I had to initiate the "upgrade my ride and pass the '98 es v6 w/95,000mi to my son" process a couple months earlier than I wanted because I was thinking I destroyed the engine by running low on oil.

Now I'm not really sure it is the engine.

Is there anything else I should be checking on/looking at. It really does sound like a wrench (or at least a bolt) is banging around in there. The speed and volume of the noise seems to be related to engine speed.

I would love to get it running again for my 16 year old to drive.

Thanks for any help!

Share this post


Link to post
Share on other sites

If you ran the engine low/out of oil and the noise is associated with engine speed, then most likely you have a rod knock.

Share this post


Link to post
Share on other sites

Yeah, three months to the day after an oil change/lube i was three quarts low. I did not have to add three quarts in the past year.

I'm not a mechanic and the last time I took any type of vehicle was 25+ years ago. But it is much louder than when I think back to my father saying "do you hear that knocking?" Maybe what he was calling "knock" was not the same thing. Would "rod knock" really sound like that? And what is it going to take to repair?

I'm pretty sure I can do some minor repairs. I replaced a master cylander and water pump on my parents old '68 Buick Sport Wagon on my own.

Share this post


Link to post
Share on other sites

You will have to first determine which cylinder(s) is knocking. You can do this by using an insulated spark plug plier and remove the ignition wire at each each spark plug one at a time while the engine is running (be careful otherwise you will get a shock), until the knock soften or goes away. This will be the cylinder where the rod bearing is burnt. Then you will have to remove the engine oil pan and remove the rod bearing for the cylinder(s) that is knocking. You will notice that the rod bearing is worn. Once the rod bearing is removed you will have to inspect and use a micrometer to check if the crankshaft rod journal is scourn and/or out of round.

If the crankshaft journal is badly scourn you can either take the crankshaft to a machine shop (this require removal of the engine) and have them machine the entire crankshaft (if this is possible), or replace the crankshaft, or replace the entire engine.

If the engine is as loud as you say then most likely a replacement engine will be the cheapest.

Share this post


Link to post
Share on other sites

Well I tried that and it seems that the noise was present and the same for each cylinder. I assumed two things during this procedure:

1. It would be OK to start and test the engine after each wire was removed and

2. I could didconnect either end of the wire.

Would either of these make a difference?

If not, what else could it be? The sound is definately a tapping sound that increases in speed with the engine.

Share this post


Link to post
Share on other sites
1. It would be OK to start and test the engine after each wire was removed and

2. I could didconnect either end of the wire.

Would either of these make a difference?

If not, what else could it be? The sound is definately a tapping sound that increases in speed with the engine.

It doesn't matter which ends you disconnect as long as it is completely disconnected and there is no arcing (high voltage can jump a small distance through air) from the wire to the cap or coil pack. The object is to remove the power stroke from the cylinder.

If this tested out OK then you will have to check the valve lifter aka HLA.

See link

http://www.topsellingcar.com/mazda626repair.html

Share this post


Link to post
Share on other sites

Hi!

Comeon......what's with all the B.S.? You checked your friggin oil and it was 3 quarts low! Obviously, you never looked after the car and now your engines cooked! Doesn't matter what anyone in here tries to tell you.....you need a new engine!

Flora

Share this post


Link to post
Share on other sites

Flora,

That seems to be the point here, I did not check my oil level for three months after an oil change. If it helps, I did have an appointment for another change on the books. I guess I should have been more dilligent but that is me when it comes to cars. In this case it is too late for that and time to move on. I would now like to know as much as possible before entrusting a stranger with the contents of my wallet.

I'm just trying to see if there are options and some are more willing than others to be helpful. If the car still runs how else can I be sure if I don't ask?

Internet forums are amazing in that people with specific knowledge are willing and able to share their expertise with others. If you happen across a forum where I may be of assistance I will certainly do my best to help you. If I don't like the way you code your website I may offer an alternative solution but I won't get irate and post a useless comment about it.

I'm well aware that you are probably correct in your assumption but thanks to people like audiqv8 I may save a couple bucks.

Share this post


Link to post
Share on other sites

Hi!

Didn't mean to be sarcastic, but if you don't check ALL your fluid levels every week, then you're going to have problems that could have been prevented! It takes me about 10 minutes to check ALL fluid levels, tire pressure, ALL exterior lights (brake, turn, tail, marker).

And NO Evert......way too old for that SHITE!

Flora

Share this post


Link to post
Share on other sites

Without actually hearing the noise, it is kind of hard to diagnose over the 'net. If the car is still driveable..that is obviously good news. Now, having worked at a shop, believe it or not most mechanics, in my experience are honest. Especially if there is a 'serious' problem, i.e. rod knock, that will have to be taken somewhere else. So, I would take it to a shop, and be prepared for the worse, but hope for the best. Good luck. Oh, and did you notice any leaks? Because if the engine was three quarts low, that is very high oil consumption and the engine may not have had far to go...

Share this post


Link to post
Share on other sites

One thing you might consider is the timing belt tensioner.

I had the same symptoms and it turned out to be a really bad tensioner, I would have never thought that but one day I went to start the car and the timing jumped and it wouldn't start. When I went to re set the timing I found the bad tensioner. I replaced it and viola no noise, I would have never thought the tensioner could have made a noise like that. BUT it is still possible you have some damage to the engine if it was that low on oil, especially if the oil pressure light came on. Keep your fingers crossed it might be something simple, but prepare for the worst

Share this post


Link to post
Share on other sites

ok, the noise is likely a bad rod knock ... you need to fix the engine immediately and not drive on it. or replcae the engine. but i would need to be present to fully diagnose it. oil pressure... oil condition... level ... leaks.... .. but the comments by audigy are correct ie pulling the plug wires to see if noise went away....

tell us what u find/

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now
Sign in to follow this  
Followers 0