Volvo Owners Club Forum - View Single Post - Bad running after new head gasket

rogerthechorister · Aug 10th, 2013, 18:14

My Sport Edition ate her head gasket (and clutch) the last weekend in May - and I've just got her back from the very helpful garage at the end of the road.

Other faults found included a very cracked exhaust manifold (changed) a turboplus little hose not properly attached, and the vacuum hose to the brake servo leaking. Oh, and a weeping rear pipe seal on the waterpump thought to have been the cause of the H/G.

No she's running like a sack of sh1t and teh question is where to start. Using NO water, using NO oil. MPG within normal bounds. It may be my imagination but I thought the temperature gauge was at first sitting a fraction high, but after half an hour on the motorway it had gone to slightly below the middle in stead of a whisker above, but it rises to straight up or a whisker above pottering in traffic. The lambda light has come on three times (pulled no 1 fuse to re-set) and so far it has stayed off after the last time. Tickover dreadful - dithering with hiccups between about 300 rpm and 800 rpm lambda light flickering on at the lowest speed (but that's probably due to zero output from the alternator at those speeds) and occasional stalling. Chasm upon initial acceleration - but then feels lively in first to the red line. But by the time one gets to 3rd and 4th is is apparent that there is a huge flatspot containing hiccups between about 3,200 rpm and 4,200 rpm, diminishing as the turboplus takes hold. Running out to the redline in 3rd (in stead of the flatspot from 5,500 to 6,000 that she's had ever since I owned her). Of course I didn't try that in 4th, ossifer it would have been illegally fast, but it MIGHT (nudge nudge) have seemed similar.

On one of my favourite test hills I am about 15 mph down at the point where I have to break or go straight over a roundabout.

Where do I start hunting?

Possiblity 1 - build an Not-quite-OBD2 reader?
Possibility 2 - AMM and throttle body and oil breather?
Possibility 3 - it feels like electrical, to my trousers, so plugs HT leads dizzy cap and rotor arm?
Possibility 4 - keep driving, the brains might be re-learning the engine?
Possibility 5 - fuel pumps and Jimathon injector cleaning? ) It is Jimathon isn't it?)

Open to suggestions here folks!

Aug 10th, 2013, 18:14	#1
rogerthechorister Rogerthechorister Last Online: Dec 16th, 2023 02:15 Join Date: May 2006 Location: Rochester	Bad running after new head gasket - cause? My Sport Edition ate her head gasket (and clutch) the last weekend in May - and I've just got her back from the very helpful garage at the end of the road. Other faults found included a very cracked exhaust manifold (changed) a turboplus little hose not properly attached, and the vacuum hose to the brake servo leaking. Oh, and a weeping rear pipe seal on the waterpump thought to have been the cause of the H/G. No she's running like a sack of sh1t and teh question is where to start. Using NO water, using NO oil. MPG within normal bounds. It may be my imagination but I thought the temperature gauge was at first sitting a fraction high, but after half an hour on the motorway it had gone to slightly below the middle in stead of a whisker above, but it rises to straight up or a whisker above pottering in traffic. The lambda light has come on three times (pulled no 1 fuse to re-set) and so far it has stayed off after the last time. Tickover dreadful - dithering with hiccups between about 300 rpm and 800 rpm lambda light flickering on at the lowest speed (but that's probably due to zero output from the alternator at those speeds) and occasional stalling. Chasm upon initial acceleration - but then feels lively in first to the red line. But by the time one gets to 3rd and 4th is is apparent that there is a huge flatspot containing hiccups between about 3,200 rpm and 4,200 rpm, diminishing as the turboplus takes hold. Running out to the redline in 3rd (in stead of the flatspot from 5,500 to 6,000 that she's had ever since I owned her). Of course I didn't try that in 4th, ossifer it would have been illegally fast, but it MIGHT (nudge nudge) have seemed similar. On one of my favourite test hills I am about 15 mph down at the point where I have to break or go straight over a roundabout. Where do I start hunting? Possiblity 1 - build an Not-quite-OBD2 reader? Possibility 2 - AMM and throttle body and oil breather? Possibility 3 - it feels like electrical, to my trousers, so plugs HT leads dizzy cap and rotor arm? Possibility 4 - keep driving, the brains might be re-learning the engine? Possibility 5 - fuel pumps and Jimathon injector cleaning? ) It is Jimathon isn't it?) Open to suggestions here folks!