11-09-2010, 09:16 PM
Join Date: Oct 2009
Mein Auto: car
Please do not drive the car until you've solved this problem. Only run the engine at idle for testing and repair purposes. Sorry but its bad. Some questions for you:
1. Is there still any smoke coming out of your tailpipe? Can you check if its steam?
2. Is there any water in your oil?
3. When you changed your head gasket, did you do a pressure test on your cylinder head? Did you change the HG yourself or get a mechanic to do it?
4. Are you still losing coolant?
5. Open your radiator's cap, fill up water till the top and run your engine at idle. Do you see tiny bubbles coming through the expansion tank? If you do, its combustion gases escaping into the cooling system through a crack in the cylinder head.
6. Do you know how to do a compression test? Do you have a compression testing gauage? Its real cheap on ebay or the shops, get one right away and conduct a compression test and post the rests here for each chamber. Check on youtube for excellent how-to videos on how to do compression tests on your engine. I mentioned that you should do this earlier. In general, when it comes to your car, do all the easier/cheaper stuff first and the harder/more expensive stuff last.
7. Post your compression test's results here for each chamber. If one or more is significantly out, then that's probably a sign of a cracked head, especially if its accompanied by numerous little bubbles in the expansion tank's water.
8. As most cracks in cylinder heads are not visible to the naked eye, the only way to confirm that its actually there is via a pressure test.
9. It is usually not advisable to attempt to repair/weld/etc a cracked head and reuse it.
10. There are some coolant additive products out there which claim to plug up leaks in cracked heads. They probably don't work, but well you can always give it a try.
In my earlier posts, I did not mention that you should do a pressure test on your cylinder head if you change the HG. It slipped my mind, and it wasn't clear that you were going to change it in the first place. However, if you changed your HG with a professional workshop, and if they did not advise you that its a good idea to have the cylinder head pressure tested due to the persistent overheating, and if you find that your cylinder head is indeed cracked, then right to sue them for the new repair or have them pay for it less the cost of the cylinder head, but with compensation for a rental car for the additional downtime. This is something the professionals should know and do automatically.
You probably have a cracked head. Start checking around for good used cylinder heads for your car. Go for the stuff that's cleaned, pressure tested to have no leaks and has a warranty. Purchase from reputable companies. Do your research first but don't pay for anything yet until you've confirmed that this is the problem on your car. Spend as little as possible on this but only buy from reliable companies. If you find a spectacular deal on a cylinder head but the origin is suspect, have the head sent somewhere for a pressure test after you receive it to confirm that its in good condition.
If you need to change your head, you need to do a top overhaul on your car. This is very time consuming. If you have a cracked head and you change it, your overheating problem will be solved permanently. If you do a top overhaul on your car, its performance will be significantly improved from before. If you do a top overhaul on your car or change the head gasket, have the piston tops cleaned of all the accumulated carbon. Yes you've spent too much on the purchase price for your car. So, if you have a cylinder head problem, consider the costs involved. It may be cheaper to purchase another 535 instead. It may be cheaper to purchase a used m30 (or m60 ) ) motor and plonk it in instead of doing a top overhaul, depending on your circumstances.
Please answer every single question I've listed here in the order in which it has been presented. Easier for me to follow
Last edited by robertobaggio20; 11-09-2010 at 09:24 PM.