Rover 25 cold start issue

Rover 25 cold start issue

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Discussion

steve y

Original Poster:

460 posts

218 months

Friday 5th August 2011
quotequote all
my 1.4 Rover 25 is acting up. when starting from cold the engine appears to run on three cylinders if I leave it alone it will slowly over about 20 seconds it picks up and runs well, fuel economy os still good, no overheating, any ideas before I hit with a branch this weekend!

Mr2Mike

20,143 posts

262 months

Tuesday 9th August 2011
quotequote all
That's often one of the signs that the inlet manifold gasket is leaking. The coolant seeps into one of the inlet ports and causes that cylinder to misfire when the engine is started until all the coolant has been expelled. If they get really bad they can hydraulically lock the engine.

MGJohn

10,203 posts

190 months

Saturday 13th August 2011
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Mr2Mike has probably nailed it for you. What you describe are classic signs.

The Inlet Manifold Gasket ( IMG ) is about six quid last time I bought one. It's not a difficult job to replace that gasket, just seven 13mm nuts secure the plastic manifold to the cylinder head. You may need to disconnect a few other items depending on access.

One way to check if this is happening to your car, it usually only affects cylinder No.4 is a simple check before starting the car next morning after not being used since the previous day. Best to remove all four spark plugs. You'll need to remove the coil packs to access the four spark plugs.

Then whilst you carefully watch the spark plug holes, paying attention to number 4 ( nearest gearbox end of engine ), get a helper to turn the engine over on the starter for 2-3 seconds. If coolant has been escaping past a worn Inlet Manifold Gasket overnight, you will see water droplets of mist being ejected at high speed from No. 4 cylinder. If you do, then a worn IMG is the problem.

If you do not, then your problem lies elsewhere.

It's easier to remove the spark plugs and do that check than remove the IMG which is not difficult, but a fiddly job and much more time consuming.

If your car in previous ownership has not had its coolant regularly renewed as recommended, then chances are the 'jiggle valve' near Cylinder No. 1 on the Inlet Manifold is blocked with crud built up over the years and miles. Not unusual to find it completely blocked with crud. It's a simple job to unblock that valve and that will enable you to bleed the cooling system correctly when renewing the coolant or indeed after refilling the drained the system prior to renewing a worn out IMG. Here's a cleaned jiggle valve in the manifold. It's the silver ball bearing in the brass housing bottom left of picture :~



Best to drain some coolant from the system when changing the IMG. Do it by undoing the little bleed bolt in the coolant tube which runs above the gearbox. This one top tight in picture of my MG ZS 1.8 :~


..


steve y

Original Poster:

460 posts

218 months

Wednesday 24th August 2011
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thanks gents that is interesting I will investigate over the weekend and report back
Steve

Mr2Mike

20,143 posts

262 months

Tuesday 1st November 2011
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Did you ever get this resolved? It's a job that should be done sooner rather than later as it's a common cause of HGF (due to coolant loss).

steve y

Original Poster:

460 posts

218 months

Wednesday 4th January 2012
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I have been laid up I'm afraid but having started to get out and about again the problem has got worse so I shall attack it this weekend
Steve

steve y

Original Poster:

460 posts

218 months

Sunday 8th January 2012
quotequote all
took advantage of the mild weather and changed the inlet manifold gasket, took me a couple of hours and some of nuts holding the manifold are a b£st*rd to get to but fired it up and ran smoothly so thanks for the assistance all
Steve

garethtp

4 posts

153 months

Wednesday 29th February 2012
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I seem to have similar problem, however i am losing no coolant and problem is intermittent and doesn't seem to occur when i use shell fuel. i was thinking fuel contamination and have had fault codes for fuel trim p1770 i think. is it this then in you opinion and if it is have you an idiots step by step guide please..................for an idiot at home...thanks in advance