Need help w/ compression numbers and leakdown test results

[Gregarious7]

The car had a fan delete for the past 6 years or so, and when the coolant reservoir cracked during the winter, I went with the 16" SPAL fan, 88 degree tstat, new water pump, but stayed with the 6 year old Mishimoto.

The car had a coolant leak that started after all this work was done. The first time I brought it in, the coolant was on the ground. Mechanic attributed to "defected" hose. All right...

It happened again about 2 weeks ago. The coolant level dropped and I only noticed after the OBC told me. This day I turned on the AC after about an hour of driving and the temp gauge went up but not in the red. More like the 2nd tick.


Car is back at the same mechanic. Suspected blown HG. Compression test results:

1) 207 PSI
2) 212 PSI
3) 208 PSI
4) 194 PSI
5) 206 PSI
6)150 PSI

Leakdown test results:
1) 1%
2) 1%
3) 1%
4) 2%
5) 2%
6) 9%


Obviously something is up with cylinder 6. Looking for advice. HG? Valves?

He is going to redo the tests after new VANOS is installed. Then I will probably list the car for sale as I'm 24 making shit money and don't have the space to work on the car myself.


Thanks

[MIKYZZ4]

Obviously something is up with cylinder 6. Looking for advice. HG? Valves?

A careful and thorough leakdown test would have revealed the answer.

[Ex36]

I find those leakdown test results a bit too good? Even cylinder 6, which has pretty poor compression comparatively, doesn't leak much.

[pbonsalb]

10% is ok for leakdown. But I agree you should sell the car. These 20 year old cars are great for DIYers but not if you have to pay a mechanic. It won't get any more reliable as it ages and the mileage goes up. Try a newer Honda, Nissan, Toyota or maybe Mazda.

[TheJordanWhitte]

A careful and thorough leakdown test would have revealed the answer.

This^

the shop should have told you why #6 was lower...

[bluptgm3]

How can they discern the difference?

[TheJordanWhitte]

How can they discern the difference?

During a typical leak down test if there's a significant leak you'll see or hear it either coming out in bubbles through the coolant or you'll hear it coming out like an air leak.

[M52 POWER!]

You can also add a few drops of oil into the cylinder to see if it has any effect.

[MIKYZZ4]

How can they discern the difference?

Here is an easy, informative example:https://www.youtube.com/watch?v=WgrfT0LFMhc

[Gregarious7]

He is going to do more tests today and I will get back to you on this.

As for selling, well I planned on keeping this car forever. But like I said, I'm 24, I should be focusing on building wealth for a down payment on a home....I think.
And not putting it into an 18 year old german sports car. The car has served me well for the past 7 years but ever since I started doing big stuff to it like the subframe mounts and diff mounts, etc etc, things have started to fail on me.

It is making me quite sad to think I'll be going from M3 to like a Camry or something...

[MIKYZZ4]

Unfortunately for you and many others,
An affordable BMW is one you are able to mechanically repair yourself,
Not one you pay a mechanic for repairs.

[TheJordanWhitte]

Unfortunately for you and many others,
An affordable BMW is one you are able to mechanically repair yourself,
Not one you pay a mechanic for repairs.

That's the only way I can afford mine

I'm about to do my head gasket and I'm giving myself two months to get it done with the limited extra time I have these days.

[pbonsalb]

The money I save by DIYing still gets spent on the car, but on modifications to make it go faster so it breaks more stuff. Its an endless cycle that will probably repeat itself until I can have a Porsche 911 Turbo.

[marvinstockman]

First, your leak started after your repair work, and is probably not engine related. If the engine is running good, leave it alone. I repeat, leave it alone.

Second, do a pressure test on the cooling system, which should show where your leak is.

[Gregarious7]

Didn't expect it to be this bad but...

The mechanic sent me pictures of the pistons inside the cylinder, which have what looks like holes in the surface. He called this getting "slapped."

He recommends rebuilding cylinders 5 and 6 and new valves. WTF

I don't understand how this could have happened. The car always drove fine. Never tracked, clutch never dropped. Always babied.

Anyway what do I do here? Wanted to keep it forever. But I can't justify whatever cost it is to replace this engine. Can I just sell as is? Maybe get $5k?

[pbonsalb]

With a bad engine, it is probably worth more like $3k.

Buy a used good S52 for $2000 and install that. Add $2000 for installation and miscellaneous. These are great cars for DIYers. Not so great if you have to pay a mechanic. They are all about 20 years old now.

[bluptgm3]

Any chance this engine has been "over rev'ed"?


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[Gregarious7]

^^Potentially before my ownership.

Anyway here's what the pistons look like.

- - - Updated - - -

[Gregarious7]

My mechanic has an S52 with 176k on it he's offering me for $1800 and $1,000 to swap it.

Does this sound like a deal? It does not sound like a good deal to me.

[TostitoBandito]

Just my opinion, but if you're gonna pay thousands for an engine swap you may as well swap in an S54. Yes it's more work, but it's a better engine.

Otherwise, ditch the car and start over. Unless you're really dedicated to making this particular car run again, you're probably better off parting it out or selling it as-is to someone who wants to swap engines. If you get another E36 M3 you can keep your mods from this car and move them over if needed.

[bluptgm3]

Kinda' looks like carbon build-up flake-off. Tough to see in a picture of a picture.

$1800 for 176K mile engine seems a bit high, $1K to swap it out doesn't seem to far off.
Do you keep the old engine? Warranty?


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[Gregarious7]

I think I've made up my mind.

The car doesnt have any symptoms besides the coolant leak, which the mechanic says it's coming from the valve.

I have $$ for an S52 swap, but I think the better move would be to put the money down on a nice 2016 Corrolla. I found a nice blue 6 speed manual with 14k on the clock.

I am going to drive the M3 home tomorrow, and keep it in my parents garage for the next 2 or 3 years, or until I have enough money for an S54 swap(guess I'll need like...$8,000?)

I can't justify selling it as is for $3,000, as I put $4,000 alone this winter into it.

Carbon build up flake off? Could this have been prevented?

[TostitoBandito]

If you're gonna tackle an S54 swap in the future I strongly recommend acquiring the skills/knowledge to do it yourself. You're gonna be forking over probably at least $6-8K in labor to pay a shop to do it. There's multiple threads in this forum detailing S54 swap builds, and some very knowledgeable people who can answer any questions. There's also a guy who sells wiring kits to help get everything connected correctly. If it's a few years out you've got lots of time to research and see what you're in for if you do this.

I'm not sure what a decent S54 itself goes for nowadays, maybe $3000 or so? Getting the engine is the easy part.

[Gregarious7]

I hope to be in a place in 2 or 3 years where I can pay for a swap like that.
I wouldn't doubt myself on an S52 swap. I think I could pull it off.
S54 swap however...is a different beast.


You are correct, however. It's a few years out and I could start collecting the knowledge and skills in order to do it. There's some excellent people in The Chicagoland area as well that I can consider contacting.

I think I will go the route you suggest. It will be a project but I can do anything I put my mind to.

You can find a decent S54 anywhere between $3.5k to $6k.

[MIKYZZ4]

My question to your mechanic is,
Valves don't leak coolant,
So what is the supposed path of this coolant leak?