1999 SC1 coolant leak, oil in coolant, P0304 code
 

Hi.. I have a 1999 SC1 (around 170,000 miles) that I drove from California to Virginia last year. Noticed a small amount of oil in overflow tank halfway across in Oklahoma. (No milkshake froth, coolant loss or overheating). I drove it on to Virginia with no problems. :)

January, I noticed a small stream of coolant pouring out from driver side. I drove it the few miles home and parked it. (Again.. no overheating, no milkshake froth, didn't even need to add fluid.. a very small leak that stopped. Thought it might be a small leak that had pooled).

Later, when I had my brother look at it, we couldn't get it to do it again... no leak showed after 30 mins of idling. He was leaving for Afghanistan, so I just left it parked until warmer weather and set about looking for a local mechanic willing to work on it.

Several months later.. after jump starting and coughing awake.. I see the leak has become larger (a steady drip on right side of radiator), but now I have a P0304 code. :(

Are these related? Is the loss of compression in #4 confirmation that I've got a cracked head even though I have no coolant loss or overheating?

What advise can you give me to figure out if this old car is worth saving? I don't really want to invest in radiator just to find out I need a new engine. Nor do I want to give up on a reliable car that gets 40+mpg that just needs a radiator and a tune up.

FYI: Replaced the intake manifold gasket in California before driving across country. I don't believe I have water in the oil. It passed the 'sizzle test'.. if you know what that is. lol

Also... does anyone know a mechanic nearly Fredericksburg, VA willing to work on an old Saturn? The ones I've talk to just roll their eyes and walk away.

I love my Saturns.. this is my 3rd SC. These forums have been a godsend. I honestly don't know what else to drive. Thanks :)

Which engine does it have? Last summer I had a leak in my intake manifold where a heater hose connects. It was hard to see at first but kept getting worse until it became quite visible. There is a repair kit available.for that problem that is talked about in other places here. It cost me about $75.00 and an afternoon's time to fix.

Thanks for responding Tom. It's a 99 SC1 with a 1.9L A/T @ 170k. The leak is more obvious now that it's warmer.. it is on the main body of the radiator (not near connections, hoses, or seals). I know radiator needs replaced, just trying to discern if it's worth the bother with oil in the overflow and lost compression on #4. I don't know what those are about or how to go about finding out. Any thoughts?

(Correction: leak isn't where I thought it was. I was going by my apparently failing memory here).

My first guess is bad head gasket. It took me about 10 hours to replace one on my 98 Escort last month. I had never replaced one before. I was told that a shop would have wanted about $1200 to do the job. The radiator is easier to replace but you need to fix the other problem or you won't have a good engine for long.

The P0304 code is telling you that cylinder #4 is misfiring. The head itself might be good but that's beyond my ability to tell you.

I THINK what Tom wants to know is if it's the SOHC or DOHC engine, right Tom? IDK, just guessing. BUT, didn't all the 1's come with the SOHC and the 2's with the DOHC? Once again, IDK, just guessing. After all, I'm NOT a mechanic. I think both are prone to defective head gaskets around #4, though. If the radiator is leaking, you'll have to replace it. You can't fix that cheap crap. Possibly some JB Weld would be a temporary repair, but I'd just get another one if it were mine. Replace the plug and see if that helps. Be ready to replace the head gasket though.

WARNING: The following post contains an unedited stream of consciousness analysis of the situation. I think it is a possible explanation, but in re reading it, it is way out there.

Somebody please find the hole in my logic and point it out so that my theory can be disqualified. I've never heard of such a situation analyzed as such, but it came out of my head so I'm sharing. Hopefully it is not a waste of time or a distraction.

I need to go clean the shower.
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Because of ring wear, some of the coolant may be finding its way into the oil pan. It'd be burned when the car is running but would run down the cyl past the rings with the car off and end up in the oil pan. Or it may be the junction that breaks off as mentioned earlier in the post.

With the insufficient seal of the intake mani near #4, a vac leak and loss of compression will lead to a misfire in #4.

To test the last statement, spray some throttle body cleaner around the intake mani where it meets the head near #4. Change in idle confirms bad mani gasket seal.

And what are the compression readings at operating temp across all 4 cyls w the throttle body held at WOT?

You mentioned reduced compression in #4 but if it was 0 I would think you would have said so specifically.

Please post compression readings and results of the vac leak test.

The tanks on the side of the radiator will give up eventually since theyre plastic. Mine failed on the drivers side of rad (do you mean right side of rad as drivers side? thats what im assuming) If your rad is leaking, its possible that the trans cooler inside the rad has failed and not motor oil your seeing in the coolant but atf. However, I agree with derf, do a compression/leak down test and go from there. check all your coolant hoses while your in there. try the brake clean/throttle body cleaner around the intake manfold.

Is it a notisable missfire or the car feels normal

You guys are awesome! :)

Tom - Yeah.. if it’s a head gasket I’m not going to bother. I’d rather invest the money into a newer car. Just have no clue what to get.. this is my third SC. I haven't driven anything else for 15 years.

Rubehayseed - Yep I am pretty sure SC1 is SOHC and SC2 is DOHC. Mine is a SOHC.

My dad always said to start with the cheap fixes first. I am tempted to change the plugs and wires, then see if some stop leak patches the radiator. I read one of the dealer bulletins recommended using their version of stop leak in some cases.

My mechanic friend doesn’t even want to work on it.. he said I should drive it until it dies then let him charge his buddies to shoot it. (Welcome to Virginia! lol)

Derf - I like your thinking, except it’s oil in the water not water in the oil. From what I’ve read on the forum.. different failures cause one or the other and sometimes both.

I have yet to do a compression test. I just have a P0304 code. So.. I don’t know if it just needs new plugs and wires or a complete rebuild. I guess that's the next step.

There has been no significant loss of coolant. I haven’t even had to top it off yet. It hasn’t overheated or bubbled up even which is why I am hopeful it’s not a blown head gasket or cracked cylinder.

Octaves - Yes.. driver’s side right, but in the coils not the plastic. I guess it could be both though. I'll check again. As far as the misfire.. it was driving fine when I parked it in January after it poured out coolant. The code didn’t show up until I started it again a few months later. It was really rough starting, but I figured it was sputtering from sitting so long. It eventually warmed up and evened out. It might not even be an issue.

Between the black stuff in the overflow, pouring out coolant, and the code.. I’ve been afraid to drive it. Don’t want to make a small problem larger.

I’ll start it up today and take pictures of the leak and the black stuff in the overflow. Any way to verify it’s burnt ATF vs Old Oil?

Thanks guys… :)

Lost compression on #4? Huh? If you didn't measure the compression, how did you reach that conclusion? ? ??????????????
Many things can cause a misfire and lost compression is only one of them.

Vac leaks intake mani
Spark gaps
gas fouling
oil fouling
arcing
coils
cracked plug
clogged fuel injector

need I go on?

We are all here trying to help you, including me. We have nothing to go by except what you type.

You tell me there is a loss in compression--I assume you've measured it. And that it's a valid part of the info to use for diagnosis. In fact my whole explanation, while completely wrong, was based on that lost compression.

My explanation is therefore bogus. So I was wrong. Whatever---it was based on your info. I care that we all get it right in the end.
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Please be careful what you list as fact vs what you include as assumptions. It may mean the difference between a solution and a never-solved mystery.
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Do the intake mani test and the compression test and let's see what we have.

Uh okay Derf.. my mistake for assuming a misfire automatically meant I have lost compression and thank you for the clarification. I didn’t realize there was a difference. I am not a mechanic, just a girl doing her best to research a problem on this site to try to save her old car and hopefully a few bucks.

You are very correct that you have nothing to go on but what I type. Trust me.. that's the ONLY reason why I bothered to point out to you that your advise kept referring to water getting into the oil.. not oil in the water. I thought it might make a difference… which apparently it has.

No insult intended. Please take it back a notch. I am doing the best I can.

All I have is the code at this point. I don’t have to means to do a pressure test myself and so far both mechanics I’ve gone to won’t even bother talking to me after I tell them I have an old saturn with oil in the overflow. They simply assume it’s a blown head gasket and walk away.

My hope with this forum question is to get armed with enough info to convince a local mechanic to help me. So… trust me I am thrilled at all your suggestions.. and willingness to help. :)

Yeah!! I was wrong again! :)
It is leaking at the hose connection on the Transcooler.
I've included picts and video for you guys.

You mean the metal connection between the trans cooler line and the lower part of the radiator (not actual hose, correct)?

To me that, along with other things in your pictures, means several things.
1) Per Octavious, the tranny fluid is mixing w coolant inside the radiator.
2) The dark stuff in the coolant reservoir is a mix of coolant and tranny fluid
3) Since that dark colored "coolant" is circulating throughout the whole cooling system, that is what you see leaking at the fitting (yes? Hard to tell color of leaked liquid)
4) Is the coolant leaking FROM the fitting where the tranny cooler line mates w the radiator, or is there a crack in the rad tank that is causing the fluid loss? If it is the former, it MIGHT not require a new rad, only a new flared end on the tranny cooler line. If the latter, it will require a new rad.
5) Head gasket: You need to do the compression test mentioned earlier in order to effectively rule out head gasket issues. You can borrow a tool for free (returnable deposit) at most auto parts stores like autozone. Be sure to read up on the right way to do a compression test -- there are many wrong ways.
6) spray around that #4 cyl at the intake mani and listen for rpm changes -- if you hear any, then there is a vac leak.
7) The reference that Rube was making about SOHC motors being known for sucking in parts of the intake gasket applies to cyl #1, not #4. But anything is possible

Please see if I have 4) correct and please post the compression test values across all cyls 5) AND the results from the spraydown 6).

Thanks Derf. Yes. Metal tube thing not rubber hose thing. Sorry. Here's a picture with arrows to point at what I'm referring to. (see image)

As far as #4 - I don't know, but it's something I can ask about when I take it in for a compression check. (It would be nice if it was a really simple fix. I'll kick myself for letting it sit so long if it is. lol) :o

Q: If it is cracked plastic on the radiator.. what are your thoughts about bypassing radiator with an add-on transcooler? (see image)

Q: Should I be concerned about coolant in my transmission?

Transmission fluid looked clear and pink when I checked the dipstick (before I started engine though. I forgot to recheck after it was warmed up).

I can't remember if I am supposed to check when engine is hot and running or cold and off. I seem to recall it was the opposite of how you check the oil, but I can't remember what my dad used to say (RIP). I'm probably confusing it with something else.

Too tired to google it.. my brain is starting to fry. :(

You CAN do the compression check yourself. It's pretty straightforward.
Do NOT pay someone like $100 for something you can do yourself!!

Google it! you just need to do the loan a tool thing to get the tool. It's free AND you learn a new skill!

If it is cracked plastic on the endcap of the radiator, then that says to me the rest of the plastic on both end caps MAY be getting brittle too. Meaning the radiator could crack somewhere else, and then you'd need a new radiator --- which of course comes with the transcooler lines in it. Plus you can get a decent radiator at Rockauto.com for $60.

In fact, you can get almost anything for $20 less than autozone at Rockauto.com.

So I'd say cracked rad plastic = new rad. Don't get a super cheapie.

Also, your present rad has tranny fluid in the passages which may or may not clean out well and may or may not have better or equal thermal conductivity properties than normal 50/50 coolant mix. Plus, depending on age and # of coolant changes, it may have deposits built up that it overall makes more sense to just replace the damn thing if you don't want to worry about it.

Coolant in your tranny VERY HARMFUL! It will wreck your tranny within the order of hundreds of miles (from) what I've read. Obviously the amnt of damage per unit time
depends on how much coolant has actually gotten through the tranny cooler lines and into the tranny --- actually that would now be a mix of tranny fluid and coolant.

Tranny fluid was clear and pink while cold says you likely have not trashed things very far. Check the owner's manual. I think you check it at operating temp w car in neutral and ebrake on -- actually I haven't owned an automatic since 91 so just look it up. You may not be able to tell the difference in the tranny fluid since if the coolant tank looks like it does as a coolant heavy mix, you don't really know what you're looking for.

It'd be nice if you could use the tranny fluid LEVEL as a hard indicator of how much coolant has filled into the tranny through the tranny cooler line, , but ultimately you really cant, because if the tranny cooler line inside the radiator is leaking, you don't know how much tranny fluid has leaked out into the coolant nor do you know how much coolant has seeped into the tranny cooler line .
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Do the compression test yourself. Here's why:
In the process you'll be pulling spark plug boots ---look for corrosion and wet oily plug boots. If they are, a flashlight down the tube will show a puddle of oil around the plug. The oil has been wicking up betw the plug and the boot (capillary action) and diverting the spark to ground.
This is the sign of a partially failed cam cover gasket, as each plug hole has a sealing gasket ring around it to keep the oil out.

Plugs, when removed, should have a light tan coating on them and still be close to the 0.040" gap. For now, regap and set aside, and note if #4 was way off.

So now you've just checked two potential causes of misfire just while on your way to doing the compression test!!!

PLUS no mechanic will touch the car if they are told it MIGHT be a head gasket issue....
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Ultimately, if I planned to continue driving this car regularly, I would:
1) replace the radiator if the crack is in the plastic or if the leak is due to the radiator side of the flared fitting.

2)Disconnect the trans cooler lines and drain and full flush of tranny including lines to get all coolant out BEFORE installing new radiator/transcooler) Consider professionally done to access all the tiny passages.
3) Drain n Full flush of entire cooling system BEFORE putting on new radiator so as not to contaminate it with ATF.

4) Repair leak at tranny cooler line fitting if it was due to the tranny line side of the flare.
5) Install new rad w integral cooler and attach tranny cooler lines to it.
6) Add proper levels of tranny fluid and 50 50 water/coolant approp for your car
7) start up and immediately check tranny coolant lines for leaks, then rest of cooling system.

Ha ha thanks for the vote of confidence Derf. I’ve watched richpin’s video on how to do a compression check and change out the radiator even. He makes everything look so easy. (as if! :eek: lol)

Let me take a step back for a second though. The initial concern about compression loss and the dreaded blown head gasket was based on the assumption that it was oil in the coolant, combined with the misfire code.

Finding out that it’s ATF in the coolant.. opens the door that maybe these are two separate events.

My brother in Afghanistan pointed out this morning that it is possible that the code could be from the rough start from sitting so long and nothing more. (That first start was really, really rough, but then it settled out). I never cleared the code, so it is possible the misfire is a non issue.

Let me clear the code and see if it happens again before I worry about compression testing.

I like your advise about the plastic on the radiator cracking. Replacing it makes sense.

Since it needs replacing, would you advise throwing some Bars Leak HDC in it and see if that slows the leak down long enough to see if it throws the code again? I don’t want to add more coolant into the transmission if I don’t have to (assuming it is).

As far as the radiator..

1. Do you think I’ll need to buy new hoses and trans line too or will professional flushing be enough? I checked RockAuto.. the radiator doesn’t come with hoses or lines. (See image)

2. As far as logistics.. after I get things flushed.. do I need to tow it or is it okay to drive a few miles with leaky radiator? How do I move it between the flush and the replacement? Afraid flushing might make small leaks bigger.

3. Coolant question: I read orange, but see green. Which one do I use? It has green in it right now (I bought it from a Saturn Tech.. so I guess green is okay?)

4. Do I need to treat new coolant system with ginger root tablets? (I read this is a thing with this year of SC).

Ahg!! It’s these little unknowns that drive me crazy and keep me fearful of working on my own car. (Well.. that and not having any tools! ha ha ha)

Thanks again Derf. Wish me luck! :)

I don't know if a simple drain n flush at home is enough to rid the coolant lines and engine passages of tranny fluid. Yes I would buy the new hoses. New rads never come w them because they fit multiple cars so the hoses would be different.

Same deal for the tranny. This is much more difficult since there are tiny passages that you cannot possibly get to clean out.

What do you guys thinK?

The misfire could very well have been triggered by the rough start. But if you've been driving it and it is still throwing that code, it may be real.
Plus it doesn't hurt to check the plugs -- so I would at least do that for now

Gotta go cook dinner. More later

I believe a radiator and cooling system flush is easy enough to do at home. there is a pour in product you can use that clean it put pretty nicely or you can use dish soap (trick from my diesel mechanic friend, he does that all the time on 6.0s, they love to lift gaskets). just dont use too much, or youll be left with foam for daaaaays. you can look that up if your unsure of the procedure, fairly simple.

Trans im not too sure on, you can get alot of trans fluid and drain now, refill, drive for a few hundred miles, and then drain again and refill. change filters at the end. I would seek professional advice on the trans, but thats what ive always done.

Green coolant is fine. once the system is flushed it doesnt matter what coolant you put in, as long as you dont mix colors. I ditched the dexcool in favor for regular green coolant in mine when I put a new rad in.

do indeed check plugs

Way back early in your posts you said your car ran rough on a restart after sitting for several months. Does it run rough now? If it runs rough enough it will set a misfire code. If it hasn't run rough since the time you remember, clear the codes and worry about your radiator.

Never, never, ever use stop leak in your cooling system. That crap should be outlawed. It will clog your heater core and cooling passages in the engine, along with passages in the radiator. Just do the proper thing and replace the radiator. It's shot, as evidenced by the trans cooler being busted and needs replacing anyway. Skip the stop leak. Once you replace the radiator, you should be just fine.

Yeah… doesn’t look good.

I cleared the codes and let it idle in place till it warmed up. Check the codes again and still getting a P0304 code (pending) with a hesitating idle, like it’s thinking about dying (even after warm). Plus it’s shaking all over the place like I broke a rear motor mount too. Uhg.

I took better pictures of the various fluids to show differences (see images)… and to be honest…. it does NOT look like ATF in the overflow. It looks like old burnt oil. Especially compared to the nice pink, clear tranny fluid on dipstick.

So.. yeah. I think I’ve got my answer. It might be fixable, but I don’t have skills, means, or money to go down that rabbit hole. :(

Time to shop for a new Saturn. :D

Thanks everyone for your time, effort, and expertise. It is greatly appreciated. :)