Looking for some answers

[johndoe]

I'm new to this forum and am here based on a referral from a fellow 3-series owner. Here's my story:

I have a 2000 323i which has about 70K miles (mostly freeway driving). It has been maintained to factory specs including extra oil changes, typically at about 7500 mi intervals rather than the 15K that the service indicator computes. All service has been by dealers, the last service at 60K performed about 4 months ago.

About 6 weeks ago I noticed the "low coolant" icon lit up. This has never happened before and the engine showed normal temp (temp gauge needle straight up). It was night and I was on the way home so I stopped and added water until the float came up to the proper level. A couple of days later the low coolant indicator came on again. When I opened the radiator cap this time "chocolate milk" came oozing out. I then checked the oil and it was down to the min. level mark. The engine has never overheated and it has never burned oil. It was only 10K mi. since the 60K service and this was very disturbing. I knew I was looking at a blown head gasket or worse, a crack in the cylinder head.

I carry extended warranty coverage through my auto insurance carrier and they said to have the car towed in for service (duh!). The car has been at the dealer for the past 6 weeks. They indeed found a crack in the cylinder head and the car is still not repaired yet. The insurance company determined that the entire engine didn't need replacing and the dealer is proceeding with replacing the cylinder head and many other parts, including a partially melted manifold (evidence that the engine did indeed overheat). The problem I have is, the temp. gauge has never indicated overheating. The needle on the gauge has always been dead center (straight up) even in trips through the desert to Las Vegas and Palm Springs. Never any hint of a cooling system problem.

I have several questions about my situation. First, how could this happen without any indication of an engine overheat? The dealer has provided no answer to this question. Second, what is the engine going to be like after this type of repair? I'm concerned that a major engine repair like this done by your typical dealer service tech will not perform like a factory built (or rebuilt) engine and that I'll be looking at engine related problems from here on out. Even though the work will be warrantied, I'm thinking of getting rid of the car once it's repaired.

I have not contacted BMW directly yet but I am very concerned about the future of this car and have definate reservations about buying another BMW. All questions and comments are welcome.

 

[codex57]

I believe most temp guages are never truly accurate. If it's within "acceptable" limits, it stays stuck in the default position (usually right in the middle) so you never really know how hot/cold your engine is.

They still hand build engines at some companies. I know people who have cars with rebuilt engines. If the mechanic knows what he's doing, it's not that big a deal.

 

[Akakubi]

Sorry to hear about your problems.

This happens from time to time. The temp sensor may have failed so it didn't let you know about the problem. I suspect that your thermostat failed along with the sensor and the car overheated. That caused a crack in the head and your further troubles.

Cylinder head and manifolds are fairly easy to replace. The dealer should be fully qualified to complete that kind of work. They do rebuilds on the new blown M3 engines that are a lot more challenging. BMW engines are in basic the same since the 60's. Mechanical parts are fairly straight forward to swap out.

Now, there will always be a risk of having this problem again in the future. But you can't even count on that with the factory assembly either. Cars do break from time to time and sometimes severely unfortunately.

You can sell the Bimmer and buy something else (or a new Bimmer ), but any new car will have it's share of potential troubles in them, especially as you go up in the mileage.

 

[frolf]

geez my coolant light is intermitant, i hope i don't have a crack in my cylinder head......

 

[Akakubi]

geez my coolant light is intermitant, i hope i don't have a crack in my cylinder head......

Check the Thermostat and Water pump. Both fail often on BMW's. I am on the second pump and third thermostat in 3 years already (only 27000 miles). My symptoms were:

1. Intermittent coolant light

2. Low or too high coolant level

3. Weird RPM's with the depressed clutch in first gear at parking lot speeds in hot weather.

The gauge never indicated overheating though. The dealer checked the engine was OK. The faulty thermostat was sending confusing signals to the ECU causing the rough RPM's. It was stuck open, so no overheating for the engine. Slower warm up though, but just barely.

 

[Kirby]

The normal assumption is that the car overheated and caused the head to crack (or warp).

But based on the fact that you never saw an over temp indication, just the low coolant, it is POSSIBLE that the cylinder head cracked FIRST due to fatigue (hard driving or just manufacturing flaw....).

The cracked head then resulted in the coolant leak, which caused LOCALIZED overheating. In that event, your temp gauge might never have shown overheating.

They should also change the oil and oil filter immediately. You had oil in the coolant (chocolate milk). Whenever you have a cracked head, you MUST assume that some water will leak into the oil journals and into the crank. If you run the engine, the water will be absorbed by the paper filter element and clog the filter. then you get a low oil pressure light that freaks you out. (I know from experience ).

Chocolate milk can also be caused by tranny fluid in the coolant, which happens if the radiator fails internally. It probably would be wise just to check the condition of the tranny fluid to be 100% safe. Not likely, but....

As Akakubi said, head replacement is not particularly difficult. I have not done it on a BMW, but just recently did a head gasket on my Volvo. I wouldn't let the repair necessarily force me to buy a new car. You may even notice that the car runs better with the rebuilt head.