General Tech Good at troubleshooting? Have a non specific issue? Discuss general tech topics here.

Dark coolant, but no coolant in the oil.

Thread Tools
 
Search this Thread
 
  #1  
Old 07-06-2014, 09:46 PM
Jmarcin's Avatar
Junior Member
Thread Starter
Join Date: Feb 2014
Posts: 21
Default Dark coolant, but no coolant in the oil.

Hi everyone -

I have a Mazda Tribute 2002, 4cyl, manual trans. 146,000 miles.

Got a bit of a pressing problem. A couple days ago I noticed that my coolant reservoir was dark. As in brown dark. No leaks under the car. No coolant in the oil. Oil looks great. Smells a bit oily, but I can't be sure if it's different than what it smells like normally. Car runs well, no issues with overheating. At least yet. and I did quite a bit of driving this month. I did 4. 5 hour drives Friday and Saturday, so 9 hours on the road with the coolant that color.

I know I need to get it looked at ASAP. I just wanted to know what you guys thought this issue might be. I have a check engine light on for my catalytic converter, but that's been on for a while (over a year, failing but not plugging). I have a manual transmission, so there would be no trans cooler in my radiator, right? Would it be a cracked head/head gasket if there was no coolant in the oil?

Other thought: back in February/March I had a coolant leak, and it turned out to be a cracked temperature casing, or something like that, positioned behind the water pump. What I did notice was that they mixed orange coolant in with my blue/green, or at least it sure seemed that way. Could this be a chemical reaction to these two types of coolant? I know it's been months, but I don't think I have even looked at it since they replaced it. I know that theory is highly unlikely. Maybe just rusty/dirty system?

However, another theory I have is that the mechanic at Firestone (where I got my oil changed last) put oil in that reservoir on accident when I had my oil changed a few months back. That is more likely, knowing how they do things at that particular store.

Any thoughts would be great. Weirdly enough this morning when I turned on my car, my radiator fan turned on right away on the cold engine. It went off a minute or so later. I thought that was strange.

Thanks again!
Jennifer
 
  #2  
Old 07-06-2014, 10:12 PM
tanprotege's Avatar
Senior Member
Join Date: Jun 2011
Location: Midwest
Posts: 2,390
Default

Jennifer: when you mix a few colors you end up with brown very quickly. Since everything seems a bit murky I would have a trustworthy shop look at the coolant. Maybe have the whole system flushed and replaced with a coolant of one color. Then see if the color changes in the next few days/weeks.

Don't jump to conclusions just because that color is weird. You know, for some time Japanese manufacturers used a brown colored coolant. How the heck would anyone notice rust if the original color is brown?

But l would jump to one conclusion: avoid that Firestone place like the bubonic plague!
 
  #3  
Old 07-07-2014, 07:06 PM
Jmarcin's Avatar
Junior Member
Thread Starter
Join Date: Feb 2014
Posts: 21
Default

Hi Tan-

Thanks for the feedback. I feel better about this now. I am taking it in tomorrow to have the system flushed. I've asked for a pressure check also, but not sure I need that. I really hope it's just a mix of the two types of coolant. I will post an update when I know something.

J

Jennifer
 
  #4  
Old 07-08-2014, 04:19 PM
Jmarcin's Avatar
Junior Member
Thread Starter
Join Date: Feb 2014
Posts: 21
Default

UPDATE: Got the system flushed. Pressure test indicated no problems. Mechanic said he didn't find anything wrong. Must have been the mixed coolants. Will keep an eye on it.

Thanks again!

Jennifer
 
  #5  
Old 07-08-2014, 07:14 PM
tanprotege's Avatar
Senior Member
Join Date: Jun 2011
Location: Midwest
Posts: 2,390
Default

Nice. Now you can trust your vehicle again.
 
  #6  
Old 07-09-2014, 07:09 AM
grim_reaper's Avatar
Super Moderator
Join Date: May 2012
Location: Queensland Australia
Posts: 7,415
Default

I've noticed in alot of Mazda's the coolant does go from green to yellow to brown ( not rusty) if not changed for a long long time. Also the overflow bottles/tanks will be stained too.
 
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Big Bopper
Mazda Tribute
1
01-26-2014 08:49 AM
taylor417
Mazda BT 50 & Pickup Trucks
1
09-03-2009 07:16 AM
blackdiamond
Mazda3
38
10-17-2007 08:05 PM
blackdiamond
Mazda CX-7
2
07-27-2007 03:04 PM



Quick Reply: Dark coolant, but no coolant in the oil.



All times are GMT -5. The time now is 04:30 AM.