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Oil (coolant) Leak *front* right

3628 Views 27 Replies 6 Participants Last post by  ixthnar

This is the first Smart mystery where I cannot find anything that makes sense.

I hit a small deer early in a 1000 mile trip. At first the damage seemed isolated to the passenger side front. A half tank of gas later the oil light started going on intermittently. I stopped and added 2 quarts bringing it to full. I stopped and added at least a quart every half tank until I got home. I used OBD2 (Torque Pro) to monitor temperatures finding everything staying in range. No smoke and no oil top side of the engine compartment. It was obviously leaking. After parking it overnight I found an oil spot about a foot in from the front passenger/damaged side.

What is oil doing way up front? No turbo and no aftermarket oil cooler. Is there some component of the PCV system up there? What else might it be?

I sure appreciate your help. A mechanic who does not known Smart cars will take a look but I need to give him some guidance / details.

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You added 2 quarts of oil to a 3 1/2 capacity engine. Sounds like you got a crack oil pan. I would check back there first.
Thanks, Smark. Were it that simple. Not a drop of oil anywhere near the back so it certainly not the oil pan. Also, the hit was passenger side front pushing the deer off the road with my speed dropping to no less than 40. There was no bottoming out or hit anywhere near the engine. Another observation is that the oil loss only happens at speed.
Is it possible that oil was spraying into the belly pan, then running towards the front and dripping out there above where you found the leak?
Thank you. Good idea. We'll find out when we get it on the lift. A broken lower breather tube is a possible source but I don't know where it is positioned under the car. Any idea where it is located?
To my knowledge there is no breather tube on the 451 engine. With an oil leak that bad there should be a puddle of oil right under the engine. Something isn't adding up here.... :unsure:
Indeed, it does not add up. I'll let you know what we find on the lift.
FYI ... I have seen cracked Smart 451 oil pan and where it leaks. Not even close, different ends of the car, in this situation.
How is brake fluid. That is the oiliest thing up front.
Needs to be checked in any case but the mystery is engine oil ... Goes in the normal place but leaks out in front
Just another thought... are you the original owner? There are oil cooler kits available for our Smarts. If one of these were installed, there could be hoses and a small oil radiator at the front of the vehicle. I think I recall reading that the Smart 452 Roadster have them
As standard equipment. This would also mean your Smart would have a larger oil capacity that an unmodified car.
Makes sense but I am the original owner and haven't added an oil cooler. (My only mod is upgrading the sound system.)
Update. Still a mystery :( Our best guess is that is only happens under load and above 4500 RPM (highway driving). This implies that the leak only happens at higher oil pressure and would spray. Maybe the oil filter is compromised somehow (it was not lose or visibly damaged). Any solutions to this puzzle would be much appreciated.
1. Leak in front was coolant. There is not oil in the coolant.
2. Back skid plat is dry except for a little coolant blown back
3. The engine is completely dry top, bottom, front, and back. The mechanic used a mirror to look into tight places.
4. The oil pan is pristine. It was replaced last year due to a crack and still looks brand new.
5. Staining on the rear axle beam and oil filter appears to be dried blood and fur
6. Above and underneath found no oil staining
7. No oil in emission/vacuum lines
8. No codes and OBD2 shows everything in normal range
8. With engine running at idle and at 3500 RPM (no load) there are no signs of oil loss
9. Next test (proof) is to top off the oil and drive at highway speeds for a quarter tank then check the oil level
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They is a oil cooler for the smart roadster. Completely different engine. Never heard of one for the 451. If there was one. It would be probably behind the oil filter hose running to a radiator up front of the car.
While there shouldn't be an oil cooler, we double checked for a cooler and for oil lines. Nope. Turns out the front leak was from damage to the radiator.
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Thanks smark. If only it were turning out to be that easy.
FWIW, these cars normally don't use much or any oil, even with the 10K oil change interval. Being 2 quarts low is really out of the ordinary. :unsure:
Indeed. Losing a quart every 150 miles or so with no other anomalies is even further beyond ordinary. Check out my progress report moments ago.
So you were not losing oil prior to hitting the bambino?
Not a drop ever. (Except last year my garage where I lived at the time, cracked the oil pan. I spotted the leak immediately and got them to replace it with a new one.)
Update. ...
When not driving, we cannot test the "spray at high oil pressure" because there is no load and the RPMs max at 3500. The oil filter was involved in the accident. While it was not visibly damaged, we will replace for want of any other options.
So you were not losing oil prior to hitting the bambino?
Correct. Not a drop. Dipstick at full for 70,000 miles (thanks Mobile 1)
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Emm, I'd check and see if the oil filter is loose. Maybe you might wanna change the oil filter. Now I know that you mentioned that there was no sign of any leaks around the engine. SO, yeah, it's a longshot.
Not loose but covered with blood and fur from the accident so I'm thinking a tiny puncture
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Just a whacky thought, but if you know someone with an action camera (like a GoPro), you could secure it under the car while you are driving and see if you can spot where the leak is coming from. It might be worth taking the belly pan off and moving the camera between runs to try and spot the leak.

The oil isn’t leaking into the coolant, right? This would indicate a blown head gasket.
I like it! Using a mirror and flashlight to view, we saw that both sides of the belly pan is also dry, no oil. This really has the mechanic's goat ... he asked all of the questions here and more.

Checked the coolant. It is down because of the radiator leak but no oil.
I have rewritten this to reflect knowledge gained and questions answered.
Mysterious Oil Loss
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