rs_1101

okay.. checked coolant the other day.. first off, it was pretty low. had to top off about 3/4 of a gallon. second, once i brought it up, i noticed little black bits floating around in there, and a moderate smell of gas. did the start up test for pulsing coolant, car passed. does this sound like a moderate blown coolant seal?
do you think this is a good candidate for block weld?

Aaron Cake

iTrader: (1)

Block weld should only be used as a stopgap temporary measure, and certainly not on an engine you plan to rebuild (the block weld totally clogs it up).

Does the car spew out clouds of sweet smelling smoke on startup? If you're missing that much coolant, I would expect it to burn quite a lot of it during the first few seconds after it is started, and also be difficult to start...

Search for the "bubble test". This will be a good indication of whether or not the engine is pushing exhaust gas into the coolant...

rs_1101

good call. actually i plan to get rid of the car within the next 2 years.. upgrade to fd or just .. you know.. get a better car. im going to do the official bubble test asap. it does smoke alittle on startup.. no wait.. it doesnt. just steams alittle for 2-3 minutes.

Sideways7

iTrader: (7)

What do you mean by steam? From the eninge bay, like from coolant that leaked out? Also, if it smokes white, its prob coolant.

locketine

he prolly means the cold gases being pushed out in the morning. I noticed the same thing in my reserve tank when I flushed my coolant, but I have a couple dead hoses so I'm guessing they were responsible since my car doesn't smoke. I would like an update on this though in case you find somethin' else is the cause besides what has been mentioned.

ilike2eatricers

I didnt have very good luck with the block weld trick on my s5 TII. It worked for about a day or 2 and they gave out. I followed the directions exactly and flushed more times than recommended to make sure I got all the coolant out and it still failed. The block weld got everywhere. I only tried it because I was getting a reman.

rs_1101

my cars an s4 na, so i have higher probability of block weld sucess.

by smoking on startup, i refer to out the exhaust. i have a pinhole leak where my pump housing meets the block that im aware of, so i can explain some lost coolant to that.
when i look in the radiator, i see in the coolant, which is otherwise >pristine<, little chunks of black material, that look to be semi-solid. my assumption would be (worst case) that its carbon. ive recently taken off my uim twice, so ive been having trouble properly bleeding the system (mostly cuz i just havent taken the time to do so). i had one overheating problem two weeks ago.. it almost got halfway up lol.. but it was due to low coolant levels, coolant wasnt returning back to the upper hose at low rpms. topped it off with about 3/4 of a gallon of water, and didnt bleed.
is it possibly just chunks of something more innocuous than carbon? im going to do the bubble test tomorrow morning probably. ive got to do alot of driving tonight so the car wont be cool enough for a lil bit. im already planning for the worst.. i figure if i can at least block weld it for a few months i can build a nice t2 setup in my garage while im bored..

ilike2eatricers

If you want to see what those chunks really are just get a prestone flush and fill kit. If the chunks were floating at the top of the rad they still might be there. You can also do the geyser test.

If you do have a blown coolant seal and do the block weld trick, expect to replace the radiator and waterpump at the least.

rs_1101

took me most of the day (due to flooding the motor twice..) but i did the block weld treatment. im not sure yet if it worked. it seems to have worked, the car feels alittle different and, no compression problems yet. i think it was blown enough to cause me to lose some compression, and today the car feels like its running stronger.
only time can tell if the seals going to hold together. i let it dry, open for a few hours, then filled with water and let sit overnight. this morning i added the antifreeze after a half assed drain of the blok weld.

ilike2eatricers

Just to warn you, you may have chunks of block weld floating around your coolant system like I did. Even though I flushed the engine over 5 times and even ran a hose with a flush kitt there were still chunks of block weld the size of small rocks and grains of sand clumped together. This happens if you have air in your coolant system. When the block weld comes in contact with air it will solidify. If you have an air bubble in your coolant system expect some chunks.

alexdimen

iTrader: (13)

why not just try to find and fix the external coolant leaks first if the engine started well and didn't have sweet smoke? also, it would have to be a pretty damn big coolant leak to get carbon in the coolant...

check your oil and spark plugs for water/rust.

rx7 SE

iTrader: (5)

My 88 rx7 has been havin the exact same symptoms lately. I can't even get it started anymore. i only have 41,000 miles on a rebuilt engine so i'm not sure why it is already doin this. I've got a few questions. I'm goin to try some of these tests u guys have said but i'm not sure wut ur doin. Wut is the "start up test for pulsing coolant" "block weld trick" or "bubble test". I'm on my last straw so any info would be very appreciated. Thanks

- i live in a very small town. lol. no one here knows anything about rotaries

WAYNE88N/A

Take your rad cap off, start the car (I know you said you couldn't, but you're going to have to if you want to do this test), and look for "expanding" coolant gushing out, or LOTS of bubbles coming into the rad after warm up, along with an exhaust smell. This will tell you if you have a problem with the coolant seals on the lower half of the rotor housings. For the upper half, she'll suck the coolant into the combustion chamber from the intake "stroke" and spit it out as smoke. Either way, time for a rebuild. 40,000 miles on a used-housings rebuild is about average, IMO...

rs_1101

flooding problems are now less frequent. plugs came up clean, everything seems clean for right now. but i suspect i still have a small leak, so the car has been delegated to short distance drivign (no trips to vegas) until i buy another car. im thinkin s5 t2. that could be fun.

rx7 SE

iTrader: (5)

-if you have a blown coolant seal, does the car start smoking progressively after you turn the car on. Meaning- it starts up w/o smoke then the longer it runs the more smoke that comes out.
???-is there anything else that can cause white smoke besides coolant?

rs_1101

whatever coolant leak i have is on the hot side of the housing. it doesnt smoke at all (except for my oil control rings) i get gas in the coolant, but no coolant out the rear end of my car.