Notices
General Miata Chat A place to talk about anything Miata

worst luck ever

Old Oct 6, 2007 | 09:59 AM
  #1  
Dow.tom's Avatar
Thread Starter
Senior Member
iTrader: (3)
 
Joined: Apr 2007
Posts: 713
Total Cats: 0
From: Odenton, MD
Default worst luck ever

Well the car is back from the headgasket problem.... but now i have another problem. The car sounds like it's running on 3 cylnders. It's slightly louder and more robust noise. I thought it was lifters but after oil change same problem. It gets louder with acceleration. but when cruising it is hardly noticeable. Any suggestions before it goes back to the shop?
Old Oct 6, 2007 | 02:35 PM
  #2  
RacingGreen's Avatar
Junior Member
 
Joined: Oct 2006
Posts: 67
Total Cats: 0
From: Germany
Default

missaligned timing belt?
Old Oct 6, 2007 | 02:38 PM
  #3  
samnavy's Avatar
Elite Member
iTrader: (7)
 
Joined: Apr 2006
Posts: 6,463
Total Cats: 327
From: VaBch, VA
Default

Check that your spark plug wires are on the right plug.
Verify there are no vaccum leaks.
Old Oct 6, 2007 | 06:31 PM
  #4  
Braineack's Avatar
Boost Czar
iTrader: (62)
 
Joined: May 2005
Posts: 80,552
Total Cats: 4,368
From: Chantilly, VA
Default

I'd say: vacuum leak, cam timing, or they furbared the headgasket
Old Oct 7, 2007 | 12:09 AM
  #5  
Dow.tom's Avatar
Thread Starter
Senior Member
iTrader: (3)
 
Joined: Apr 2007
Posts: 713
Total Cats: 0
From: Odenton, MD
Default

it happened just randomly, it ran fine, than out of no where...
Old Oct 7, 2007 | 12:17 AM
  #6  
patsmx5's Avatar
Elite Member
iTrader: (16)
 
Joined: Aug 2007
Posts: 9,406
Total Cats: 559
From: Houston, TX
Default

Get a timming light and crank the engine up. put the sensor on each sparkplug wire and make sure each cylinder is getting a spark consistantly. Change the sparkplugs, as one could have cracked or failed, and they're relatively cheap. While they're out, inspect them closely. Reading the plugs will tell you which cylinder is missing and if it's covered in gas, it's probably not getting spark or has very little compression. If your not gettting consistant spark to each cylinder, check the sparkplug wires for proper resistance using an ohm meter.

If all that checks out good, run a compression check. This will help you determine if there is a mechanical problem and which cylinders it's effecting. If this checks out ok, you've likely got a fuel problem. Again, reading the plugs will help you determine if the problem is just one cylinder or if it's all 4.
Old Oct 7, 2007 | 12:37 AM
  #7  
Dow.tom's Avatar
Thread Starter
Senior Member
iTrader: (3)
 
Joined: Apr 2007
Posts: 713
Total Cats: 0
From: Odenton, MD
Default

well the plugs were gunky on the threads and gray on the electrodes. dont know what that means. Not wet like it's spitting.
Old Oct 7, 2007 | 04:49 AM
  #8  
Savington's Avatar
Former Vendor
iTrader: (31)
 
Joined: Nov 2006
Posts: 15,442
Total Cats: 2,106
From: Sunnyvale, CA
Default

Photos? Could be metal shavings.
Old Oct 7, 2007 | 10:55 AM
  #9  
Dow.tom's Avatar
Thread Starter
Senior Member
iTrader: (3)
 
Joined: Apr 2007
Posts: 713
Total Cats: 0
From: Odenton, MD
Default

okay... changed plugs. No good. Removed a spark plug wire at a time and put back on. Car suffered when off, returned to robust noise when back on. Put timing light on each plug and they were consistant. Finally i pulled my laptop up and used megasquirt to see my vacuume. 22 @ idle. I'm out of ideas, next?
Old Oct 7, 2007 | 11:29 AM
  #10  
socal pat's Avatar
I'm Miserable!
 
Joined: Aug 2007
Posts: 94
Total Cats: 0
From: Sun City, Ca
Default

Originally Posted by Braineack
I'd say: vacuum leak, cam timing, or they furbared the headgasket
That would be mu guess. A friend of mine had the same symptoms on a fresh motor. We checked the oil for metal with a magnet, as well as all the checks the OP did. Turns out he left off the locator pin when aligning the gasket. It was off just enough to catch the edge of a piston and acted sort of like a playing card on the spokes of a bicycle wheel. Made a strange noise that almost made you whince.
Old Oct 7, 2007 | 11:35 AM
  #11  
Dow.tom's Avatar
Thread Starter
Senior Member
iTrader: (3)
 
Joined: Apr 2007
Posts: 713
Total Cats: 0
From: Odenton, MD
Default

yeah it sounds like a playing car on a bike! that's the sound. But could it come out of no where? I mean it wasn't like this when i got it from the shop. Now a hose did pop off and the car overheated to 2/3rds but it didnt make that noise immediately afterwards. Nor did it after i took it back to the shop. Should i take it back to the shop again? Could the gasket of moved and be hitting the piston? Also, i seem to still be losing oil, and i still have milky fluid on the rad cap, they said it's cause there was oil left in the hoses still.

thoughts?
Old Oct 7, 2007 | 12:06 PM
  #12  
patsmx5's Avatar
Elite Member
iTrader: (16)
 
Joined: Aug 2007
Posts: 9,406
Total Cats: 559
From: Houston, TX
Default

continue my list. compression check will tell you if it's a mechanical problem or a headgasket. Your shop says the oil in the coolant it from the oil left in the hoses. If there's water in the oil, it's the headgasket for sure. I would definately flush the cooling system soon so you can get the oil out and monitor it. If your loosing oil, you need to find out where it's going. Is it burning it or leaking it?
Old Oct 7, 2007 | 12:15 PM
  #13  
magnamx-5's Avatar
:(
iTrader: (7)
 
Joined: Jul 2006
Posts: 8,255
Total Cats: 4
From: nowhere
Default

Tom if there is something fubard with it and they did the HG not to long ago make them fix it obviusly something is outof wack cause i highley doubt anything you have done has screwed the motor up like that. I would not pay a dime to get the sucker right. Worst case scenario you might hae a misalinged HG best case maybe a failing harmonic balancer mine made abit of noise under accel before it fell off. Check the bolts down there and make sure you haven't been fishing around. if they overtorqued the bolts or maybe just used shitty bolts they could fail.
Old Oct 7, 2007 | 12:18 PM
  #14  
Braineack's Avatar
Boost Czar
iTrader: (62)
 
Joined: May 2005
Posts: 80,552
Total Cats: 4,368
From: Chantilly, VA
Default

remember, i changed my headgasket and it failed within 25 miles.

rough idle, overheating, 3-cly type running are clear signs of a messed up headgasket.
Old Oct 7, 2007 | 12:18 PM
  #15  
socal pat's Avatar
I'm Miserable!
 
Joined: Aug 2007
Posts: 94
Total Cats: 0
From: Sun City, Ca
Default

I like Pat's list, but would substitute leakdown for compression test. It will tell you everything a comp test will and then some.
Old Oct 7, 2007 | 12:24 PM
  #16  
Dow.tom's Avatar
Thread Starter
Senior Member
iTrader: (3)
 
Joined: Apr 2007
Posts: 713
Total Cats: 0
From: Odenton, MD
Default

i dont have anything for a compression test, can i use a leakdown tester and crank and use it as a compression test?
Old Oct 7, 2007 | 12:25 PM
  #17  
Dow.tom's Avatar
Thread Starter
Senior Member
iTrader: (3)
 
Joined: Apr 2007
Posts: 713
Total Cats: 0
From: Odenton, MD
Default

i think it's burning oil honestly, i dont see any on the ground ever.
Old Oct 7, 2007 | 02:15 PM
  #18  
Braineack's Avatar
Boost Czar
iTrader: (62)
 
Joined: May 2005
Posts: 80,552
Total Cats: 4,368
From: Chantilly, VA
Default

i think they screwed up your headgasket install. id take it back to the shop.

leakdown test would tell you right away.

if you put 100psi of air into each cylinder you can record how much loss is in each.

say you put 100psi in #4 and you only get a reading of 80psi. you know that you are losing 20% of your compression.

then you can listen for the air where it's exiting. if the radiator, its going into the coolant passages, so bad headgasket. if oil filler cap it could be the rings or headgasket throught the oil passages. if intake, the intake valves. if exhaust, the exhaust valves.
Old Oct 7, 2007 | 07:10 PM
  #19  
LOLA - 92's Avatar
Senior Member
 
Joined: Oct 2004
Posts: 1,161
Total Cats: 0
From: SWAMPS OF FLORIDA !!!
Default

Exhaust Manifold Gasket leak?
Old Oct 7, 2007 | 08:24 PM
  #20  
Dow.tom's Avatar
Thread Starter
Senior Member
iTrader: (3)
 
Joined: Apr 2007
Posts: 713
Total Cats: 0
From: Odenton, MD
Default

could be that, but do these things arise from no where?

Thread Tools
Search this Thread

All times are GMT -4. The time now is 10:18 PM.