MG Rover ZR 2005 Misfire
Hello Guys Another Day Another Car and New Problem Hope all of you help me as you guys always do Thanks
Got MG Rover ZR 2005 (55) Plate took for an MOT failed as following
005 Exhaust Emissions Carbon Monoxide Content at idle excessive [7.3.D.5]
006 Exhaust Emissions carbon monoxide content after 2nd fast idle excessive [7.3.D.4]
007 Exhaust Emissions hydrocarbon content after 2nd fast idle excessive [7.3.D.4]
008 Exhaust Emissions Lambda reading after 2nd fast idle outside specified limits [7.3.D.4]
Other then that when car was tested for MOT it was misfiring and Engine Block was really hot, Radiator water pipes were rock hard. Engine Block is shaking like a faulty tumble dryer, Rocker cover and Headgasket has slight oil leak but there is no sign of mixing water with oil or increase in car Temperature
Engine Management light was also ON when I scan OBDII discover following code
P0170 Fuel Trim Bank 1
MOT tester think Head Gasket is on it's way out but I need second opinion before I start taking head off.
Hope to hear from All you guys
With the engine hot and the coolant tank cap removed, does the coolant bubble out?
Do the radiator fans work above 95 degrees? If you remove the plug from the coolant temp sensor - in front of the engine near the gearbox either brown or black - then the fans should run constantly. This will prove the circuit is working.
Do a compression test to see if one or two cylinders are low.
The fuel trim fault is due to the misfire which is causing all the readings to be wrong. The Cat may be damaged by unburnt petrol hitting it.
Thanks for your reply mate I will go through all your suggestions tomorrow morning and will let you know my findings
Head Gasket Fault Finding Steps
1. With the engine hot and the coolant tank cap removed, does the coolant bubble out?
Coolant tank had bit of pressure it was hard to open but there was no movement in the water
2. Do the radiator fans work above 95 degrees?
2.b If you remove the plug from the coolant temp sensor - in front of the engine near the gearbox either brown or black - then the fans should run constantly. This will prove the circuit is working.
I have removed the black Plug under the Coolant bottle (I don't know if it was the right one) but noting happened.. as car was still running fan came itself On and after a minute it's stop it self so it's look like the circuit is working
3. Do a compression test to see if one or two cylinders are low.
Compression Test Results:
1st let the car run for 10 minutes as advised by Compression Test Equipment Manual
2nd Test First 3 Banks Reading is as follow:
9 Bars, 140 Psi, Colour Band Solid Green, Test Time 10 Sec
9 Bars, 140 Psi, Colour Band Solid Green, Test Time 10 Sec
6 Bars, 81 Psi, Colour Band Red/White, Test Time 10 Sec
As Bank 3 has low compression value then the other two I retested Bank 3 again... this time I got following value:
5.8 Bars, 81 Psi, Colour Band Red/White, Test Time 13 Sec
As it's slight drop in Bars so I thought it may be because Engine is cooling down so I restart the car again for another 10 minutes then tested again and now the results as follow:
6.2 Bars, 90 Psi, Colour Band Red/White, Test Time 13 Sec
6 Bars, 90 Psi, Colour Band Red/White, Test Time 13 Sec
It's clear it has a low compression around Bank 3 and 4 and this is a side where I can see little bit of oil leak
What you guys think and what steps I should take plz let me know
I would say that the head gasket has probably gone between 3 and 4 cylinders. 90 psi is too low. It probably hasn't gone as far as the water jacket so no bubbling in the expansion tank. It looks like it hasn't gone between the water jacket and the oil ways so no emulsified creamy oil.
Looks like head off to repair the damage.
So it's Head Gasket then.. so I am starting the work from coming Sunday hope every thing will go smooth.. As I have never change Head gasket on ZR before is there any thing I should be aware of before I start working on it.
These are MUSTS!
1. head must be skimmed no matter what
2. you must buy new head bolts (stretch type) as the originals will have stretched (ignore the measuring the length advice and reusing)
3. you must fit a new thermostat - dead easy with the head off and very difficult with the engine fully built
4. you must fit the 2 locating dowels between head and block
5. use only a quality head gasket
6. inlet manifold gasket should be renewed
7. you must torque the head down in the correct sequence exactly as specified
8. before refitting the hydraulic tappets, you MUST squash them closed in a vice before putting them back in. The oil will come out of the small hole in the side and they do take some force to close them. If you do not, they will have fully opened while out of the engine and then when you come to start the engine there will be no compression and it will not start.
9. make sure you mark the cams and cam wheels before removal (or take a picture on your phone) and remember the crank is not at top dead centre on these, it is 90 degrees passed so the lug on the crank pulley is at 3 o'clock.
K16 None VVC Engine
my MG ZR has K-16 Non VVC Engine as it is Twin CAM and 10 head bolts are fitted in between both CAM shafts in two Rows as these CAM shaft's are not stopping me un-bolting these Engine Head bolts I am under the impression if I will unbolt these CAM bolt I will be able to lift whole head after removing Timing belt do I have to go through hydraulic tappets steps?
Last edited by car-auctions; 03-07-14 at 16:37.
Reason: up date vehicle Engine information
Every machine shop I have ever used to skim the head will not touch it unless it is stripped down. And remember when refitting the head with the cams in place if you choose to do this, that the pistons must be down and level i.e. 90 degrees after top dead centre or the valves will hit the pistons as you torque down the head.
Progress So far:
I have manage to take head off without removing camshafts and valves, the machine shop I use they are happy to stripped the head and then refit every thing back on for me (with extra cost)
As advised I am taking pictures of every step and within couple of days I will upload pictures of all steps before starting refit process there is couple things which I will need your advise so plz keep an eye on my post
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